Cast:
Patty Lane: Patty Duke
Cathy Lane: Patty Duke
Martin Lane: William Schallert
Natalie Lane: Jean Byron
Ross Lane: Paul O'Keefe
Richard Harrison: Eddie Applegate
Sue Ellen Turner: Kitty Sullivan
Ted Brownley: Skip Hinnant
Gloria: Kelly Wood
J.R. Castle: John McGiver
Nikki Lee Blake: Susan Melvin
William Smithers: Ralph Bell
Mr. Brewster: Charles White
Sammy: Sammy Smith
Jonathan Harrison: David Doyle
Kenneth Lane: William Schallert
T.J. Blodgett: Alan Bunce
Robert Carson
Jerry Hauser
Mrs. Marlow: Natalie Masters
Miss Gordon: Phyllis Coates
Louie: Bobby Diamond
Monica Robinson: Laura Barton
Kathy Garver
Mrs. MacDonald: Margaret Hamilton
Alice: Alice Rawlings
Rosiland: Robyn Miller
Alfred: Jeff Siggins
Maggie: Alberta Grant
Eileen: Ann Walford
Lane family dog: Tiger


Theme Song:
Meet Cathy, who's lived most everywhere,
From Zanzibar to Barclay Square.
But Patty's only seen the sights
A girl can see from Brooklyn Heights --
What a crazy pair!

But they're cousins,
Identical cousins all the way.
One pair of matching bookends,
Different as night and day.

Where Cathy adores a minuet,
The Ballet Russes, and crepe suzette,
Our Patty loves to rock and roll,
A hot dog makes her lose control --
What a wild duet!

Still, they're cousins,
Identical cousins and you'll find,
They laugh alike, they walk alike,
At times they even talk alike --
You can lose your mind,
When cousins are two of a kind.