#'s indicate season in which actor appeared on the series.
Jean Sagal as Kate Foster
Liz Sagal as Allison Foster
Donnelly Rhodes as Art Foster 
Patricia Richardson as Beth McConnell 
Jon Caliri as Michael Gillette 
Barbara Barrie as Aunt Margo 
Jonathan Schmock as Billy Batalato 
James Vallely as Charles Kincaid 
Michael D. Roberts as Mr. Arrechia 
Anne-Marie Johnson as Aileen Lewis 
Genre: Situation Comedy
Running Time: 30 mins
Syndication History: USA Network, late '80s-early '90s
4 Apr 84 One Drives, the Other Doesn't
11 Apr 84 Lust
18 Apr 84 First Day
25 Apr 84 Bad Chemistry
2 May 84 Dueling Feet
16 May 84 Separate Birthdays
23 May 84 Heartache
30 May 84 Bombshell
1 Dec 84 If We Can Make It Here...
8 Dec 84 Do You Believe in Magic?
15 Dec 84 Dream Girls
22 Dec 84 O Come All Ye Faithful
5 Jan 85 Man for Margo
12 Jan 85 The Boy Next Door
19 Jan 85 Memories
26 Jan 85 Two Girls for Every Boy
2 Feb 85 The Write Stuff
9 Feb 85 Commercial Break
16 Feb 85 Old Movies
23 Feb 85 September Song
2 Mar 85 Funny Girl
23 Mar 85 The Day of the Rose
30 Mar 85 Where's Poppa?
This sitcom about twin high-schoolersóone zany, the other seriousówas reminiscent of The Patty Duke Show some two decades earlier.
There were two principal differences, however: in Double Trouble real-life twins played the leading roles (while Patty Duke had played both roles herself), and The Patty Duke Show lasted three times longer.
When the show premiered in the spring of 1984, it was set in Des Moines, with the twins in high school. Jean Sagal played Kate Foster, the headstrong, impulsive twin; and Liz Sagal played Allison, the studious, sensible one. Also featured were Donnelly Rhodes as their widowed father, Art; and Pat Richardson as Art's woman friend, Beth McConnell.
When the show returned in the winter of 1984, the twins had moved to New York City to live with their aunt, with Allison studying fashion design and Kate hoping to become an actress. Rhodes and Richardson were gone. Joining the cast were Barbara Barrie as the girls' aunt, Margo Foster, author of the "Bongo Bear'' kids' books; James Vallely as Charles Kincaid, and Jonathan Schmock as Billy Batalato, two actors who also lived in Margo's townhouse; and Michael D. Roberts as Mr. Arrechia, Allison's pompous fashion instructor.
In real life the Sagal twins were the daughters of the late film director Boris Sagal and the younger sisters of Katey Sagal of Married . . . with Children.. †