Peter and Jimmy think they have it made when their teacher, in assigning a project called The City, divides the class into committees by where they live.
Peter gets up on a Saturday morning, all set to head off to play basketball with Jimmy. There's just one problem that he's conveniently overlooked its Fudge's birthday and some of Fudge's friends are coming for a party.
Ann has to leave early to help Jean Tubman prepare for a dinner party and Peter is not home yet. Sheila, who's taken a babysitting class, volunteers to watch Fudge.
Peter and Fudge have a day off from school and Ann reminds Warren that they were to spend the day with him at his office, since she will be too busy at the dental office to bring them with her.
With Jimmy, Peter eagerly anticipates the first day of school until the night before, when Warren and Ann tell Peter that Fudge will be attending as a kindergartener.
Peter and Fudge are sitting at the dining room table building with a box of Lego blocks. Peter has an elaborate satellite in progress while Fudge is having trouble with a train station. As usual, the two boys end up in a fight.
It's "Career Day" at school and Peter has volunteered Jimmy's father, an artist, as a guest speaker. This has upset three people - Peter's parents who are hurt because Peter didn't volunteer them, and Jimmy, who is afraid his father will embarrass him.
As told through the eyes of ten-year-old Peter Hatcher, the two-hour made for television movie entitled Fudge-a-Mania tells the story of the Hatcher family as they embark on a summer vacation in Maine - one they'll never forget.