Lizzie inadvertently starts a hurtful rumor about Kate when she doesn't make it to the cheerleading squad but Kate does. Miranda takes the blame for the rumor and Lizzie watches a full-scale war develop between the two, while Lizzie tries to work up the courage to admit that it was she who began the rumor. Matt keeps a pet lizard at home whom he names Lizzie. 

Social embarrassment looms when Lizzie's mother insists she wear the "cute" red unicorn sweater her grandmother knit for her on picture day. Matt falls sick and takes a leave from school to stay at home. 

Lizzie is excited to go on a co-ed camping trip with her science class, but soon loses interest when her mom steps in as an emergency chaperone. Matt and his dad are having trouble cooking dinner in the absence of Jo. 

Lizzie and Miranda are invited to a Danny Kessler's pool party. But, Lizzie is denied permission by her parents to attend the party, as it turns out to be the same day as her grandmother's birthday. 

Lizzie is fed up of being an average student and finds that she is good in rhythmic gymnastics. She joins the school team and takes part in an inter-school contest. Kate conspires with Larry Tudgeman to sabotage the contest but Gordo and Miranda save the day for Lizzie. Eventually, Lizzie wins the contest but gives up rhythmic gymnastics. 

Gordo thinks that his teacher Mr. Pettus is adopting a partisan approach by awarding him only 'B' grades instead of 'A's. So he plans to switch projects with Lizzie. Meanwhile, Matt changes his name to "M-Dogg". 

Aaron Carter comes to town to shoot a Christmas-themed music video. Matt, Lizzie, Miranda and Gordo decide to sneak in to meet him. While Matt is successful in doing so, Lizzie and her friends are chased around the studio by the security guards. Eventually, Miranda gets to meet him and finally Lizzie and Miranda get to feature in the music video alongwith Carter. 

When a babysitter is unable to make it, Lizzie's parents reluctantly let Lizzie babysit her brother, Matt. She soon discovers that babysitting is not as easy as it looks, even with her friends' help. 

Lizzie decides to run for school president and starts to become very egotistical, shrewd and obsessed with winning. Matt makes up an imaginary friend named Jasper, which worries his parents a lot. 

For a class project, Lizzie and her classmates are paired up for marriage. Lizzie becomes jealous, when Miranda ends up with Ethan Craft. She soon discovers that Kate (who is paired up with Larry Tudgeman) wants Ethan to leave Miranda at their "10 year reunion" (which is a part of their project) and Lizzie has to find a way to tell her. Matt builds a cave in their house and his dad joins him there to live in solitude. 

Lizzie becomes friends with a goth girl and develops bad habits and a bad personality. Miranda and Gordo are concerned with this and decide to help Lizzie become her old self. Matt is given the freedom to sleep late at night but after initial euphoria, Matt starts having problems in staying awake during daytime. 

Lizzie and Miranda go shopping for their first bras with Lizzie's mom embarrassing them along the way. Meanwhile, Matt asks for Gordo's help to direct a martial arts film to enter in a contest. 

In order to stand out of the crowd, Gordo sports a 1950s attire and starts listening to old music. But he is disappointed when the trend catches on with the whole school, including Lizzie and Miranda. Matt and Lanny try their hand at creating a record in order to get their names featured in the Guinness book of world records. 

Lizzie gives Miranda a bad review when she plays the lead role in the school play. Miranda soon realises that singing is her main talent, rather than acting. Matt and Lanny want a pair of walkie-talkies but Matt's parents refuse to pay for it. So Matt sells everything he owns, including his bed and clothes to get the money. 

Lizzie is in a frenzy because Ethan Craft has asked her to sit with him at lunch the next day. Matt boards the wrong school bus and spends a day at Lizzie's school where Lizzie has a harrowing time when everyone is besotted with Matt, including Ethan Craft. 

Lizzie becomes obsessed with volunteering after a school volunteer project. Meanwhile, Gordo becomes obsessed with winning the Science Olympics, and Matt goes power crazy with his new hall monitor job. 

Lizzie has to attend a class charity drive and looks forward to spend the whole day with Ethan. At home, Matt irritates Lizzie with his magic tricks and he handcuffs himself to Lizzie and loses the key. Meanwhile, Jo finds the key and decides to remain silent about it so that Lizzie and Matt learn a lesson about family bonding. Lizzie has a hard time keeping Matt hidden from Ethan for the whole day leading to embarassing situations. 

Lizzie and her friends lie at their homes and sneak off to see an R-rated film that everyone else at school has seen. While at the movie theatre, Lizzie saves a man who is choking on a candy ball and gets interviewed by a TV crew. Lizzie's parents come to know of it and Lizzie gets busted. Meanwhile, Matt is having a fair at school and Jo decides to build a velcro-wall in which kids can jump onto. 

Lizzie and Miranda feel neglected, when Gordo spends more time with his new girlfriend, Brooke (Kyla Pratt). They are unable to come to terms with the fact that Gordo has a girlfriend now and he is drifting away from their group. Meanwhile, Matt learns about "percentages" from his father and starts accepting bets from his friends, but he eventually lands in trouble when his mother finds out about this. 

Gordo becomes Ethan's math tutor because he needs the money to buy a new stereo. However, once Lizzie shows Ethan an easier way to do math, he decides he wants Lizzie as his tutor, and not Gordo. Meanwhile at home, Matt and his friend Oscar try to emulate superheroes by trying to help people. But their noble intentions are not well received by people around them as they unknowingly cause harm to them. 

Ethan invites Lizzie, Gordo and Miranda for bowling, while on the same day Lizzie's dad wants to spend some quality father-daughter time with her. Meanwhile, Matt and Lanny plan on what they can do to stop the bully, Heywood Biggs from picking on them. 

A big-time movie director offers to follow Gordo around to see a day in the life of a regular kid. Gordo starts saying rude things to the camera, though, and even coaxes Lizzie and Miranda to tell each other's secrets in front of the camera. Meanwhile, Matt gets blamed for all the troubles created by Melina and he admires her qualities as a troublemaker. 

Lizzie is selected as a model to participate in a fashion show presented by "Teen Attitude" magazine at a local mall. Her modelling stint earns her fame in the school but she is annoyed when everyone starts treating her differently because of her new status. Meanwhile, Matt and Lanny buy a hammock from a shop but when it turns defective, the shopkeeper refuses to take it back. Matt and Lanny then decide to teach him a lesson. 

Lizzie wants to become the "Dungeon mistress" for the Halloween fright night at school. However, Kate becomes the dungeon mistress and Lizzie is forced to become a clown. Peeved with this, Lizzie, Gordo, Miranda alongwith Matt use the Sanchez family's Halloween traditions to play a prank on Kate. 

Hoping to win a trip to Miami, Lizzie, Miranda and Gordo team up to enter the school's "Fact-athlon" contest. Mr. Digg coaches them for the quiz in an unconventional way but they eventually end up losing. Matt and Lanny hire a drummer and start their own rock band, but in the end they call it quits. 

Lizzie discovers that Larry Tudgeman has a crush on her and when he asks her out, she reluctantly agrees to go out with him. Surprisingly, Lizzie enjoys the date, but eventually in the end, they part ways. Meanwhile, while cleaning up some junk, Matt and Sam find an old Soap-Box Derby racer and decide to restore it. 

Gordo becomes obsessed with a Dungeons & Dragons type board game which was gifted to Lizzie by her grandmother. His obsession causes his grades to drop and Lizzie and Miranda take the help of Matt to bring Gordo back to his senses. Meanwhile, Matt has to observe wildlife for school project but eventually, Sam and Miranda's father end up climbing a tree and watching a bird's nest. 

After being absent from school, Lizzie finds out that her project partner is none other than Kate Sanders, who was also absent on the same day. After their initial hostility, they both start getting along together. But after the project is over, they both take potshots at each other but not before sharing a smile and realising that they still have a bond between them. Meanwhile, Matt is convinced that he has pscychic powers and has a hard time convincing his parents about it. 

Miranda is smitten with a boy in her class, but is too nervous to talk to him. So, Lizzie decides to help her out. But a misunderstanding leads the boy to believe that Lizzie has a crush on him. Gordo is sick of listening to all the girl-talk between Lizzie and Miranda and decides to indulge in some male bonding with Matt. 

Gordo installs video cameras all around the school, revealing embarrassing secrets about the students. Further, he plans to enter his film into the district film competition. Miranda gets upset on hearing this as the film showed her in bad light. However, Gordo pleases all when he showcases the film without revealing anyone's identity. Meanwhile, Matt decides to become a stuntsman and tries out various stunts. 

Gordo feels self-conscious when he sees Ethan Craft and other boys growing up sooner than him. He tries to be "manly" by trying to do manly things but in the end he decides to have a Bar Mitzvah which would initiate him into adult life. Meanwhile, fed up with all the complaints about Matt's pranks, Jo decides to hand over the task of disciplining the kids to Sam. 

Lizzie has her first boyfriend, named Ronnie, who is the local neighborhood paper boy. Lizzie is completely besotted with him and Miranda and Gordo are fed up listening Lizzie talk about him all the time. However, Lizzie is heartbroken when Ronnie breaks up with her to go out with a girl from his school. In the end, Lizzie is consoled by Gordo. Meanwhile, Matt needs only one baseball card to complete his card collection but only Melina has it. Melina agrees to give the card to Matt, but only if he does the homework and other chores for her. 

Lizzie, Miranda and Gordo are obsessed with a Spanish game show, "El Oro de Montezuma" ("The Gold of Montezuma"). Miranda's cousin Carlos from Mexico City is scheduled to compete on the show and Lizzie and her friends decide to be in his team. Meanwhile, Matt and Lanny play an extreme version of Hide and Seek. 

Lizzie and her Mom become best friends after reading a book in social studies. She even convinces Gordo and Miranda to bond well with their parents. But in the end, Lizzie realises that it would take some time to be more intimate with her mom. Meanwhile, Matt and Lanny find a chimp which creates havoc in the house, for which they both are blamed. 

Claire is head of the cheerleaders and throws out Kate after she hurts in her arm. Lizzie helps Kate regain her popularity and a place in the cheerleading squad. Matt is excited to be in a school play and acts arrogant about it. He starts bossing around but in the end he learns a lesson about humility. 

Miffed with her parents for not raising her allowance, Lizzie gets her first job as a busboy at the Digital Bean. But to Lizzie's surprise, it is a lot worse than she ever suspected it would be. Matthas some problems with Melina and turns to Miranda for advice. In the process, he develops a huge crush on Miranda, much to her horror and Gordo's amusement. 

Lizzie, Miranda and Gordo have a fight and stop talking to each other. Meanwhile, Kate and Gordo, Miranda and Larry, Lizzie and Ethan, are paired up for a treasure hunt-styled school project. Matt comes to know of it and unknown to them, beats them to the finish line. As the school project progresses, Lizzie, Miranda and Gordo realise the worth of their friendship and renew their ties. 

Lizzie baby-sits Matt once again, with Matt deflating their father's prized autographed football. They work all day to get it back. 

Gordo encourages Lizzie to finally do something about her crush on Ethan Craft; that is, ask him to the Sadie Hawkins Day dance. But when Lizzie does this she's disappointed when Ethan tells her that he likes their relationship as friends and doesn't want to risk changing it by going out with her. Matt and Lanny open a club in their backyard and their beverage becomes quite popular but in the end they are forced to shut it down. 

Lizzie and Matt switch bodies for a day, a la Freaky Friday. Matt (in Lizzie's body) and Lizzie (in Matt's body) go to each other's school and end up in amusing situations. They both solve each others problems at school but the next day they return to their normal selves, leading Lizzie to wonder whether it was all a bad dream. 

Lizzie has a hard time standing up for Miranda when she is accused of shoplifting. This creates a rift between both of them, causing them to choose different dance partners in their dancing class. However, in the end both realise their mistake and become friends again. Meanwhile, Matt hosts a talk show alongwith Lanny on the internet. 

Lizzie starts feeling inferior when she realizes a lot of the other kids around her have special talents and skills that they've developed, including Gordo with his filmmaking and Miranda with her violin. Matt is scared after watching a horror movie and is convinced that their house is haunted. 

Lizzie wants to be voted "best dressed" in her school and wants to buy an expensive pair of jeans. But her Mom refuses and insists on buying her clothes at discount store. Meanwhile, Matt has problems adjusting with his newly acquired fame due to his participation in an advertising commercial. 

While Lizzie and Kate are stuck working together for the Spring Fling committee, Lizzie sees Kate knock over the bust of the school's founding principal. When Principal Tweedy (Phill Lewis) discovers this, he threatens to cancel the Spring Fling unless the person responsible comes forward. Kate keeps quiet so Lizzie decides to take the blame and is excluded from attending the fling. Lizzie is sad until every one at school comes over to her house to have the fling at her place, while Kate is left all alone at school. Meanwhile, Matt and Lanny have a hard time sharing a bike. 

Lizzie begins mentoring a seventh-grader girl named Andie, who begins to mimic her characteristics and behave like Lizzie. After initial liking, Lizzie starts to dislike Andie and advises Andie to stop aping her blindly and be herself. Finally, Andie ends up being Kate's protege. Meanwhile, Matt must earn a merit patch with his Wilderness Cadets group or he would be demoted. Sam tries to help but ends up harming himself. 

Frankie Muniz comes to town to shoot his new movie and befriends Lizzie. Lizzie and her friends learn a little about the pressures of teen stardom. Matt becomes Lizzie's secretary and tries to use his sister's fame for his own advantage. 

Miranda has a misconceived notion that she is fat and begins to skip meals to look slim for a music video directed by Gordo. Miranda begins to develop a eating disorder and Lizzie and Gordo are concerned about it. However, in the end Lizzie convinces Miranda to be comfortable with her body and persuades her to stop dieting. Meanwhile, Matt shows a great artistic potential and his parents encourage him to pursue it. However, he gets into trouble when he trashes their house and uses their family car as canvas for his paintings. 

Gordo skips a grade and gets promoted to high school. After initial euphoria, Lizzie and Miranda start to miss Gordo. Gordo too feels lonely at the high school but pretends to like it in front of Lizzie and Miranda. In the end, he returns back to middle school.Meanwhile, Matt and Lanny plan to try out for the cheerleading squad at school but Sam feels that it's not a "manly" thing to do. Sam tries to lean away Matt from cheerleading by doing some "manly" things with him but in the end he encourages Matt to try for cheerleading. 

Kate is having a big birthday party and she invites everyone from her class including Lizzie, Miranda and Gordo. But Lizzie and Miranda's parents refuse to let them go for the party as there would be no adults around. So, Lizzie, Miranda and Gordo lie at their homes and go for the party. But the party goes horribly wrong and Lizzie calls her mother for help and eventually all three are punished for lying. Meanwhile, Matt and Sam are selected to star in a commercial for Cardio Punch Sports Drink. 

A major food fight erupts in the cafeteria and Lizzie, Kate and Larry stay afterschool to clean up the mess until someone confesses up to starting the fight. Matt and Lanny miss their bus while on a school fieldtrip and end up wandering in the city all by themselves. 

Lizzie and Gordo are giving Matt's toys away at a Christmas charity drive which has an unlikely-looking Santa Claus --- Steven Tyler of Aerosmith, and he's assisted by Nobby Frostybump (Shelley Berman), a senior citizen playing one of Santa's elves. Lizzie wants to put an elaborate float together for an upcoming Christmas parade. She needs and gets help building it from Gordo, however she has stiff competition from Kate and her cousin Amy who have their float built by professionals, and Larry Tudgeman who's building a Star Wars-themed Christmas float. To make matters worse, her efforts to build the float are compromised by Nobby, who really apparently thinks he is one of Santa's elves. Nobby usually spends time at a senior citizens home, which had a plumbing problem, and the McGuires & Gordo offer to help fix it. However, the process of doing so gets in the way of Lizzie's ability to finish her float.

Lizzie falls asleep, and has a dream where she's visited by Nobby Frostybump, and then family members and friends posing as Christmas legends in order to try to show Lizzie the true meaning of Christmas. When she wakes up, Lizzie forgoes building the float to help Nobby, and remains content with herself. But much to the surprise of everyone, her float is found fully assembled and being used by "Santa Claus" who sings his own rendition of "Santa Claus is Coming to Town." 

Lizzie tries to get all eleven of her pictures in the school magazine, but it won't be easy with Kate as editor. So, Lizzie's family and friends hatch up a conspiracy to get the job done. 

Lizzie becomes an agony aunt and starts giving advice on the school website, but soon finds it difficult to handle. Matt feels threatened by a new prankster in the class who is gaining more popularity than him. 

Lizzie's friends and family play a who-done-it mystery game at her house. 

Lizzie and her friends are graduating from middle school. They all sign each other's year books, except Gordo, who can't decide what to write in Lizzie's book. He eventually writes something heartwarming and is rewarded by a kiss from Lizzie while posing for the class photograph. Matt is unable to bear the summer heat at home and thinks of various methods to keep himself cool. 

All the kids at school are asked to put their hand prints on a wall, symbolising unity. A water pipe bursts in a wall in Matt's room and to Lizzie's horror she'll have to share her room with her brother until the repairs are done. 

Parker, a girl that Gordo likes turns down his offer to go with him to the school dance because of his height. Matt has to write a school report on his ancestors but he makes his report sound quite 'interesting'. 

The McGuire family members are all psyched about making their annual journey to Grubby Gulch, a "Wild West" theme park, after missing last year's trip. Lizzie, Gordo and Miranda are reluctant to go for the trip but Matt is very excited about it. 

Lizzie, Miranda and almost every girl in their class have a crush on their new English teacher Mr. Keith, who is from Scotland. Meanwhile, Fredo the chimp comes to stay at the McGuire's home and Matt isn't too happy with it. With some intervention from Jo and Sam, soon Matt and Fredo are getting along very well. 

Doris Roberts guest stars as Gordo's grandmother who now lives a more relaxed lifestyle since the last time she and Gordo met. This irritates Gordo but impresses Lizzie and Miranda. Meanwhile, Lizzie's parents fall ill and are confined to bed. Matt and Lizzie thus enjoy their unsupervised freedom at home. 

Miranda is throwing a big house party, and refuses to invite Larry. Lizzie feels bad about it and decides to give him a makeover and sneak him into the party. Matt and Melina make friends with an elderly couple as a part of a school project and find that the old couple is just like them. 

Gordo receives a credit card by mail with a $5,000 line of credit and he uses it to direct a "big-budget" film. Matt is having problems finishing his school science project in time. 

Lizzie feels uneasy, when her dad becomes best friends with Mr. Dig. Meanwhile, Matt is having a hard time with super strict teacher. 

After setting a new school record in gym and then beating Ethan Craft in arm-wrestling, Lizzie is invited to play touch football with the "cute guys". But Lizzie is worried when Ethan calls her a "dude" and she feels that she is losing her feminity by playing football. Unknown to Matt, Fredo the chimp completes his math homework which gets him good grades in school and praise from his parents. 

Kate sees Lizzie, Miranda, and Gordo at the audience of a kiddie TV program called "Clover and Daisy's Magic Train" and blackmails them about it (in school). Matt showcases his house as a 'Dust Museum' and shows the visitors around.