- Drew Barrymore as Charlie McGee
- David Keith as Andy McGee
- Martin Sheen as John Rainbird
- George C. Scott as Captain Hollister
- Louise Fletcher as Norma Manders
- Heather Locklear as Vicky Tomlinson
- Art Carney as Irv Manders
- Moses Gunn as Dr. Joseph Wanless
- John Landis as Dr. Pynchot