Mr Wilson goes for a haircut in preparation for a magazine taking his picture for an article. Unfortunately, Dennis scares the barber and the back of George's hair is accidentally shaved off.

Mr. Wilson takes Dennis camping on a cold and windy mountainside, so that Dennis will be able to join the Junior Pathfinders and Mr. Wilson will improve his own odds of winning a Best Citizen award.

A new regulation says no one can walk on the grass in the park. When a policeman chases Dennis and his friends off the grass, Henry talks to the policeman. Henry gets a ticket for walking on the grass in order to talk to the policeman.

Thanks to Dennis, Mr. Wilson forgets the combination to his new safe.

George and Henry buy an investment property only to find out it's haunted.

Chaos ensues when Dennis handcuffs Mr. Wilson to Tommy while rehearsing a school play and there's no key.

With Mr. Finch offering a free 5-minute shopping spree for the 50,000th customer at his pharmacy, Mr. Wilson tries to calculate the exact moment that it will happen so that he can walk through the door and claim the prize.

When Henry becomes sick, Mr. Wilson manages Dennis' Pee Wee League baseball team.

Mr. Wilson believes he's a millionaire when he inherits his aunt's estate.

Dennis' school teacher stops by to tell the Mitchells that Dennis scored high on an IQ test at school. They try to help Dennis with his intelligence, and later find out there was a mistake in the grading.

Mr Wilson gives Dennis a coin with Good Luck written on it for mowing his lawn. Dennis thinks it is a lucky coin, and he seems to have a lot of good things happening to him.

Dennis, Henry, and Mr. Wilson go out in search of the perfect Christmas tree to chop down. As problems arise, their quest turns into quite an odyssey.

After Mr. Wilson takes a temporary position at the bank, Dennis opens up a bank account and stops at the bank daily to check on his money and keep Mr. Wilson company.

The Mitchell's host a circus act for a cub scout event. They need someone in the back end of a lion costume. He asks Mr Wilson to help out.

Hoping to be selected as a delegate to a bird lovers' convention, Mr. Wilson hosts a reception for the organization at his home. The program includes a special guest who does actual bird calls. However, after seeing a sign for the meeting in a music shop window, ("Remember the Bird"), two beatniks think the occasion is to honor a music legend, and they show up to turn it into a jazz program.

Mr. Wilson wagers his large magnifying glass, betting that Dennis can't refrain from talking to him for five straight hours.

Dennis' school is putting on a play about all nations. Each student has to ask someone to represent a different nationality to be in the play. Dennis asks Mr Wilson and Mr. MacTavish to represent Scotland. The 1961 Miss Scotland appears.

With Mr. Wilson's help, Dennis enters his frog in a frog jumping contest.

Mr. Wilson has a memorable birthday after he decides to leave Dennis his gold watch in his will.

George is expecting a visit from his Uncle Ned, a rocker-chair addict. When Ned arrives, he is active, fit, and energetic. Ned forces George and Henry into a fitness program.

Mr. Wilson's plans for a quiet evening with his coin collection go awry when he unexpectedly has to babysit Dennis, Margaret, and Seymour.

Dennis gets a new Private Eye Detective Kit and has fun with Tommy solving crimes. When they hear that Mr Wilson's wallet was stolen, Dennis and Tommy use their new found skills to find the culprit.

To help Martha, Mr. Wilson hires a housekeeper. But this backfires when the stern housekeeper won't let Mrs. Wilson do anything, and rearranges the kitchen cabinets to Mr. Wilson's dissatisfaction.

The store owner tries to keep a dog out of his store. He puts the dog outside, and when Mr Wilson leaves the store, he follows Mr Wilson home. Now, Mr Wilson tries to keep the dog out of his yard.

Dennis has a history project for school to take pictures of historical places around town, and then write a composition about them. Mrs Wilson suggests Mr Wilson help Dennis because he has a movie camera.

Henry buys an antique car to enter the Horseless Carriage Road Race. He hopes the win the prize and become the president of his and Henry's local chapter for the club. Dennis talks Mr Wilson to take him & his friends on a drive in the car.

George hopes to become a member of the Pioneer Club in order to get a free cabin vacation each year. He agrees to help Dennis' Junior Pathfinders Club build a fire with just two sticks in order to assure his membership in the Pioneers.

Dennis gets an old chest from Mr Wilson who thinks the chest has nothing of value. Dennis & Tommy play pirates with the items in the chest, and even draw up a map to a pretend treasure. Mr Wilson later finds it and thinks it is real.

Dennis, with a loose tooth, wants to visit a new dentist who gives presents to first-time patients. But when Dennis's tooth falls out before he can go to the dentist, he convinces Mr. Wilson to go in his place so Dennis can still get a present.

Mr Wilson installs his own burglar alarm after a series of burglaries in the neighborhood. Dennis thinks the new neighbor is the stocking bandit. This is the last episode with Joseph Kearns who died after filming the episode.

Dennis & Tommy get Mr Quigley to coach their baseball team. Mr Quigley hopes it improves store sales. He manages to get the Dodgers to play an exhibition game for the town. Mr Wilson is said to be going on a trip which explains his absence.

George's Uncle Ned visits while George is out of town (no longer in series). He decides to plant flowers to win a flower contest in the summer. Dennis says he will help plant the flower bulbs so he does not have to play with Margaret.

While Mr. Wilson is out-of-town, his brother, John, moves in with Mrs. Wilson.

Dennis' school is raffling off live chickens, and Dennis gets John Wilson to buy tickets. He wins and wants to cook the chicken but Dennis won't allow it.

A bully at school beats up Dennis. John Wilson helps him to learn to fight.

When Dennis sets out to join a club, John Wilson begins to question his sanity.

John Wilson and Henry Mitchell compete in the games at the community picnic.

John Wilson is writing an article about witch doctors. But some strange occurrences and odd accidents convince his new neighbors that he really is a witch doctor and is out to hex them.