Dennis' School has a contest that any student who collects the most stamps wins a trip to Cape Canaveral and meet an Astronaut. Unfortunately, Dennis comes down with the chicken pox right when he is about to win.

Dennis and his friends help a boy who is poor and feels that he doesn't fit in prepare for and play in the school basketball game.

Mr. Wilson enters a contest that requires having children, so he passes Dennis and his friends off as his kids.

Mr. and Mrs. Wilson have a Chinese girl that is staying with them while Mr. Wilson is interviewing the girls father for a magazine article.

Dennis hears Mr.& Mrs. Wilson argue and spreads it around the Neighborhood and soon some of the neighbors think that the Wilson's have split up.

Dennis gets a job for a day delivering Circulars for Mrs. Elkins. But, When he swaps territories with another kid, he gets blamed for throwing the circulars in a trash can.

It's Children's Day in Court, and Dennis is the Judge! Mr Wilson goes to court to dispute a ticket he received for violating a city ordinance.

Dennis thinks that Mr. Wilson is broke so he tries tries to help him out.

Mr. Wilson gets mixed up with Gypsyes and they think he is one of them.

Dennis gets a new Principal, Mr. Spivey who is very strict at his school. Mr. Spivey and Dennis get off on the wrong foot at first However, Johnny Brady takes note of that and because he wants to be on the pitcher on the school baseball team. So, he sets Dennis up by drawling a picture on the back of his paper making fun Mr. Spivey's height. When Mr. Spivey finds it he naturally assumes Dennis is the one that drew it so he punishes Dennis by kicking him off the baseball team and keeping him after school. As the news travels Mr. Wilson, Mr. Quigley and Mr. Finch all go to the school a few minutes apart and talk to Mr. Spivey each claiming to be Henry Mitchell to stand up for Dennis. Mr. Spivey gets confused but soon realizes he misjudged Dennis and ends up apologizing and putting Dennis back on the school baseball team.

Mr. Wilson gets a chimpanzee from the San Diego zoo which causes chaos at the Motel that the Wilsons and the Mitchells are staying at.

Mr. Wilson's nephew visits him and gives Mr. Wilson and Dennis a ride in his navy truck and then Mr. wilson and Dennis get trapped on the navy base.

Henry is thinking of getting a new job which takes place neer the Asian river. Dennis does what he can to prevent it including running away from home.

Mr. Wilson hangs out and plays with Dennis and his friends the whole day to gather information for a magazine article of what young children do in this day and age.

Mr. Wilson is doing a column for the newspaper that he thinks will have every single women in town happily Married. However, it ends up getting Sgt. Mooney in a love triangle with Miss Cathcart and Miss Tarbell.

Dennis visits a hermit out in the woods, Mr. Wilson thinks that he fought in the civil war, so he tries to get his life story.

Mr. Wilson has written a book on his Uncle Ned's life for his publisher. Uncle Ned however does not want the book to be published So Mr. Wilson goes up to Uncle Ned's house to try and reason with him. The only thing is that Uncle ned has gone down to Mr. Wilson's house to talk with him as well. Now it is up to Dennis to try and keep Uncle Ned from meeting the publisher until Mr. Wilson can return home again.

Mr. Wilson tells Dennis he isn't feeling well to get Dennis to leave him alone and then Dennis tells the whole neighborhood, So they all think that Mr. Wilson is very sick.

Dennis and his friends do an indian rain dance to try to get Henry out of playing golf with his boss.

Mr. Wilson thinks he has discovered big-foot prints in his yard which end with hilarity results.

Dennis becomes confused about love when he hears his parents and Mr.& Mrs. Wilson argue with one another.

Dennis is appointed by the Mayor to go to Washington and ask the Senater to pass a bill for a national Forest.

Mr. Wilson is convinced that he is allergic to Dennis because he sneezes every time Dennis is around. It is later discovered that it was only the hair tonic that Dennis had been using what was causing Mr. Wilson's allergies.

Dennis sees baby booties knitted for Mr. Wilson's golf clubs and he thinks that the Wilson's are having a baby, So he goes around and tells the whole neighborhood.

Dennis accidentally ties an important note that belongs to Mr. Wilson on a pigeon, so Mr. Wilson, Henry, Tommy and Dennis go to where the pigeons roost at night at a spooky house to try and get the note back and end up in the middle of a collage fraternity initiation meant for new fraternity members. After a bunch of twists and turns they find the pigeon with the note tied on it.