 | Joey Cramer als David Scott Freeman |
 | Paul Reubens als Max (voice) |
 | Veronica Cartwright als Helen Freeman |
 | Cliff DeYoung als Bill Freeman |
 | Sarah Jessica Parker als Carolyn McAdams |
 | Matt Adler als Jeff (16 years) |
 | Howard Hesseman als Dr. Louis Faraday |
 | Robert Small als Troy |
 | Jonathan Sanger als Dr. Carr |
 | Richard Liberty als Mr. Howard |
 | Raymond Forchion als Detective Banks |
| Cynthia Caquelin als Woman Officer |
 | Ted Bartsch als Night Guard Brayton |
| Brigid Cleary als Technician #2 |
| Michael Strano als Technician #3 |
 | Parris Buckner als Scientist #1 |
 | Robyn Peterson als Scientist #2 |
| Philip Hoelcher als NASA Officer |
 | Julio Oscar Mechoso als Hangar Guard #1 |
| Butch Raymond als Hangar Guard #2 |
| Chase Randolph als Lieutenant King |
| John Archie als Agent #1 |
| Tony Calvino als Agent #2 |
| Rusty Pouch als Gas Station Attendant |
| Robert Goodman als Tourist Man |
| Peter Lundquist als Newscaster #1 |
| Jill Beach als Newscaster #2 |
| Kenneth Ian Davis als Kid in Mustang |
| Arnie Ross als NASA Technician |
| Fritz Bronner als NASA Technician |
| Albie Whitaker als Jeff 8 year |
| Alan Silvestri | Original Music Composer |
| James Glennon | Director of Photography |
| Mark H. Baker | Original Story |
| Jonathan Sanger | Executive Producer |
| John W. Hyde | Executive Producer |
| David Joseph | Producer |
| Matt MacManus | Screenplay |
| Dimitri Villard | Producer |
| Robert Wald | Producer |
| Jeff Gourson | Editor |
| Randal Kleiser | Director |
| Michael Burton | Screenplay |
| Mark Damon | Executive Producer |
| Michael Novotny | Art Direction |
| Mike Fenton | Casting |
| Valorie Massalas | Casting |
| Scott Jacobson | Set Decoration |
| William J. Creber | Production Design |
| Jane Feinberg | Casting |
| Robert Wald | Sound Designer |
| Robert J. Litt | Sound Re-Recording Mixer |
| Emile Razpopov | Sound Designer |
| Craig Haagensen | Camera Operator |
| Peter Donen | Visual Effects Supervisor |
| Craig Boyajian | Visual Effects Coordinator |
| Gary Holt | Gaffer |
| Jim Borgardt | ADR & Dubbing |
| James H. Armfield | Still Photographer |
| Dessie Markovsky | Sound Designer |
| Gabriel C. Ell | Construction Coordinator |
| Steve Maslow | Sound Re-Recording Mixer |
| Diana Johnson | Hairstylist |
| Jack Bennett | Special Effects Supervisor |
| Elliot Tyson | Sound Re-Recording Mixer |
| Lillian O. MacNeill | Script Supervisor |
| Mary Lou Byrd | Costume Design |
| Kenneth Karman | Music Editor |
| Jordan Klein Sr. | Underwater Camera |
| Ron Goodman | Camera Operator |
| Tim Webb | Sound Recordist |
| Walter A. Gest | Sound Recordist |
| Peter Lyons Collister | Second Unit Director of Photography |
| Malcolm R. Harding | Production Manager |
| Peter Bogart | First Assistant Director |
| Randall Badger | Second Assistant Director |
| Thierry Coup | Set Designer |
| Courtney Brown | Stunt Double |
