Dennis Quaid
Lt. Tuck Pendleton
Martin Short
Jack Putter
Meg Ryan
Lydia Maxwell
Kevin McCarthy
Victor Eugene Scrimshaw
Fiona Lewis
Dr. Margaret Canker
Vernon Wells
Mr. Igoe
Robert Picardo
The Cowboy
Wendy Schaal
Wendy
Harold Sylvester
Pete Blanchard
William Schallert
Dr. Greenbush
Henry Gibson
Mr. Wormwood
John Hora
Ozzie Wexler
Mark L. Taylor
Dr. Niles
Orson Bean
Lydia's Editor
Kevin Hooks
Duane
Kathleen Freeman
Dream Lady
Archie Hahn
Messenger
Dick Miller
Cab Driver
Kenneth Tobey
Man in Restroom
Joe Flaherty
Waiting Room Patient
Andrea Martin
Waiting Room Patient
Jason Laskay
Scrimshaw's Henchman
Frank Miller
Scrimshaw's Henchman
Shawn Nelson
Wendell
Christine Avila
Lab Technician
Alexandra Borrie
Lab Technician
Jenny Gago
Lab Technician
Robert Gounley
Lab Technician
Grainger Hines
Rusty
Mike Garibaldi
Cop
Richard McGonagle
Cop
Terence McGovern
Travel Agent
Robert Neches
Lab Guard
Rance Howard
Supermarket Customer
Chuck Jones
Supermarket Customer
Laura Waterbury
Supermarket Customer
Kurt Braunreiter
Lab Assault Henchman
Robert Gray
Lab Assault Henchman
Brewster Sears
Lab Assault Henchman
Alan Blumenfeld
Man with Camera
Jeffrey Boam
Lydia's Interviewee
Sydne Squire
Stewardess
Paul Barselou
Man on Plane
John Miranda
Man in Elevator
Jordan Benjamin
Little Kid in Mall
Roberto Ramirez
Chef
Virginia Boyle
Shopping Lady
Herb Mitchell
Camera Store Clerk
John Harwood
Lab Henchman
Neil Ross
Pod Computer (voice)
Charles Aidman
Speaker at Banquet
Joe Dante
Vectorscope Employee (uncredited)