Teenager Patty Lane and her worldly identical cousin Cathy navigate family and high school life.
Cast:Patty Duke , Jean Byron , William Schallert , Paul O'Keefe , Eddie Applegate , Alberta Grant , Kitty Sullivan , Sammy Smith , Jeff Siggins , John C. Attle , Timothy Neufeld , John Spencer , Skip Hinnant , Robyn Millan , Harry Packwood , John McGiver , Alice Rawlings , Joanne Mariano
Frankie Avalon's car breaks down in front of the the Lane house so he asks if he can use their telephone. Once Patty realizes who it is she is determined to spend some time with Mr. Avalon.
Patty needs to have her tonsils removed and her surgeon just so happens to look like Troy Donahue, much to Patty's delight.
Patty's rival Monica throws a party but doesn't invite Cathy. Patty gets Cathy invited but at the expense of losing Richard on a date to Monica, so Patty decides to skip the party. That is until she learns that a musical group needs a lead singer and there is a possibility of a record deal at the party.
Richard's parents leave for a week so Patty invites him to stay at the Lane house while they are gone. Things seem to be going okay until some of Richard's actions begin to rub some of the family members the wrong way.
Patty paints a painting at school but everyone is afraid give their honest opinion about it. Will they put their money where their mouth is when the painting goes up for auction?
Patty takes a shy student under her wing in order to teach her how to be more popular. But Patty faces a dilemma when she proves to be too good of a teacher.
An Interpol spy, and friend of Cathy's father, comes to visit the Lane family. But Patty thinks he is there on official business.
Richard gets into a fender bender and Patty becomes an unwilling witness in the potential court case.
Patty begins to doubt Richard's commitment to her, and when Richard mistakes Patty for Cathy she sees this as an opportunity to put Richard to the test.
Patty has to stay in bed because she is sick. But Patty simply doesn't have time to be sick. She has too many things to do.
After being stood up on a date with Richard, Patty refuses to speak with him. This time, Ross tries to patch things up.
Patty gets a job as a nurses assistant at the hospital. Unfortunately for her dad, he ends up at the hospital too.
The family camps out in the backyard as a test run for their summer vacation.
A friend suggests to Cathy that the Lanes wouldn't stop her from becoming an exchange student because she has worn out her welcome there. So Cathy decides to prove her friend wrong by signing up for the program.
With her History grades faltering at school Patty befriends a new student, who just happens to be good at History.
Patty, Cathy, and Ross are constantly on the telephone, so Martin puts his foot down by placing restrictive limits on their calls.
Patty intends to prove that she is capable of watching Ross for the weekend while their parents are away.
Patty wants the family to pitch in to buy Martin a birthday present. But trouble begins when the family gets the wrong idea about what present Martin wants.
Patty befriends a trumpet-playing musician who is down on his luck, and invites him to stay with the Lanes until he can land a gig. But will he wear out his welcome first?
Patty volunteers her dad to give a speech for one of her classes at school. The only thing she forgot to do was ask her dad first.
Ross begins having trouble with a bully at school. Meanwhile, Patty falls for the bully's brother so Cathy takes it upon herself to come to Ross' aid, with the help of Richard.
In order to make a few bucks Patty offers to take care of a woman's dog. A dog that just happens to have a list of peculiar needs.
Patty gets tricked into dumping Richard, so in order to save face she invents a new boyfriend.
As part of a school project Patty writes a letter to a Soviet politician. While she is stunned to get a reply, she is even more surprised when the State Department gets involved.
What starts out as a simple misunderstanding between Patty and her dad turns serious when Patty believes that her dad no longer trusts her.
After Patty receives a dress from Cathy, who is on vacation in Paris with her dad, she decides to throw her first adult party. But things get complicated when Uncle Jed arrives.
To teach Patty a lesson, Cathy encourages the family to trick Patty into thinking she has psychic abilities. After Patty starts giving readings to her classmates an actual psychic takes interest in her abilities.
When Martin thinks that Patty doesn't follow through with her chores, she reinforces that belief when she fails to make a bank deposit for him. He decides to teach her a lesson but ends up having the tables turned on him.
Patty and Ross buy three kittens from a neighborhood kid but before they can sell them for a profit they lose track of each cat. One by one, Cathy, Martin and Natalie each find one of the cats. And they all want to keep one for themselves!
After friends of Patty and Richard's get married they decide to do the same. At first this idea sounds like a dream, but later turns into a nightmare.
In order to secure a date from a neighborhood boy, Patty convinces Ross to do some chores for him.
Ross' only chance to get into a basketball club is for Patty to date the club's president. Unfortunately for Patty, she can't stand the guy.