Mr. Peepers shows up for his first day of work at Jefferson High and has initially a difficult time. His classroom isn't ready and the other science teacher wants him gone. Music teacher Miss Dean is welcoming and Principal Gurney wants to give him a chance.

Mr. Peepers agrees to give a speech on wildflowers for Mrs. Gurney at the same time Mr. Gurney needs him to play for a chess championship. Gym teacher Charlie develops a workout routine for Mr. Peepers but he gets stuck in a basketball hoop.

Mr. Peeper's gets his hand stuck in a fish while trying to retrieve his tie pin. His bad day continues when his first paycheck get blown into an air pipe and he has to crawl in it to get it back.

The teaching staff pitches in on various custodial jobs when the janitor needs to be absent. Mr. Peepers is assigned to to run the striping machine which goes amok, leaving white stripes everywhere.

In Mr. Gurney's absence, Mr. Peepers takes a matter of student discipline to Vice-principal Velvet Clave. When he protests the harshness of the penalty, he finds himself out of a job.

It is 'Bring your Pet to School Day' and Mr. Peepers must hide a Holstein cow from the visiting school superintendent.

On the strength of several published scientific articles by Peepers, a seed company agent tries to coax him to come work for their firm at a big salary increase over teaching. He declines when he finds he'd have to compromise his principles there.

Mr. Peepers asks Miss Remington to the school dance but the constant presence of Harvey Weskitt complicates things. And there is the matter of the broken punch dispenser.

Noticing a definite anti-social trend in one of his students, Peepers decides he's not getting enough fatherly attention, so he takes the boy fishing. A day of bungling only yields one undersized fish, for which the game warden brings them to court.

Robinson finds a Mr. Monfrede in his classroom as the new science teacher when he returns from military duty. While Mrs. Gurney tries to recall something she's to tell Mr. Peepers, he says his goodbyes and prepares to leave the job he loves so much.

Mr. Peepers meets Nancy Remington's parents and manages to destroy a family possession.

Foolishly forgetting an obligation to do a speech for fire prevention at Remington's house, Peepers accept Weskit's invitation to play in the bowling league championship at the same hour. At Remington's, he has to sneak out to get to the game, but has trouble getting back in time.

A law firm representative informs Mr. Peepers that he may be the heir to the estate of a deceased English great-aunt.

Mr. Peepers' inheritance becomes a legal fact and he prepares for his journey to England to collect the money. After frantic last-minute preparations, he boards the boat, only to find himself as cabin mate to an elegant British aristocrat, Peter Rhodes-Downing. Downing holds him in complete contempt until he finds out that Mr. Peepers is to collect some money; then his attitude changes quite quickly

Robinson Peepers and his new-found friend, Peter Rhodes-Downing try to elude the purser in an effort to see the first class quarters.

Mr. Peepers and his new friend Peter Rhodes-Downing arrive in England. To compare English customs with those in the United States, Robinson visits an English junior high school, then takes a sight-seeing tour of London.

Mr. Peepers is in England to hear his uncle's will read. He's most interested in getting his uncle's insect collection.

Mr. Peepers returns from England and is met by Nancy and the Weskits. But a financial crisis arises as they live it up at a fancy restaurant.

To celebrate Mr. Peepers' birthday, Wes decides to bake him a cake. Meanwhile, Nancy and Marge make a secret trip to the doctor and confirm their suspicions: Nancy is going to have a baby.

Aunt Lil is so thrilled to hear she will be a great-aunt that she takes some time off to visit Jefferson City and offer her congratulations. When there, she decides to stay a few days, and has Mrs. Gurney call her boss to say she's ill.

Robinson Peepers' in-laws, Ma and Pa Remington, return from an out-of-town trip to learn that they are to be grandparents.

Mr. Peepers take out on his motorcycle in search of a flighty canary and breaks up a sedate woman's club meeting.

Mr. Peepers and his father-in-law Pa Remington decide to spend a day fishing, but they're after no ordinary catch. For fifteen years, Pa has been trying to hook a large trout, unofficially known as "Old Colonel." He thinks the assistance of his scientifically-minded son-in-law may do the trick this time.

A surprise party is arranged for Nancy Peepers who is leaving Jefferson City Junior high school to await the arrival of the stork.

Harvey Weskit returns from a visit to his in-laws with a large gift of money, which he hopes will buy him membership in an exclusive country club. Mr. Peepers knows the club president, and arranges a golf date between him and Wes. Meanwhile, Mr. Peepers takes a gardening job at the club in order to earn extra money, but this threatens Wes' chances of being admitted as a member

Harvey Weskit borrows a cabin cruiser from a friend of his wealthy father-in-law, and invites the Peepers to join him and Marge on a cruise. Wes is self-appointed captain, but his piloting leaves something to be desired.

Mr. Peepers and Wes hear that Elaine Stritch is playing at a nearby theater, so they attend, hoping to convince her to appear at their parent-teachers meeting.

When a new ballet teacher is hired at Jefferson City Junior High School, all are shocked to learn that after school hours she dances at a roadside cabaret. Mr. Peepers goes to investigate

Mary McCarty and Mae Barnes help Mr. Peepers enact "The Life Story of Wally Cox".

Mr. Peepers gives the official commencement speech at the junior high school graduation exercises. He also asks for a raise in salary, in view of the coming baby. When the Superintendent of schools refuses the raise, Mr. Peepers considers applying for employment at a nearby military academy.