George Maharis
— Dr. Dan Summit
Cameron Mitchell
— Arnold Chester
Margaret O'Brien
— Pam Rhodes
Robert Walker Jr.
— Major Barry Wolfe
Susan Oliver
— Carla Burke
Jeremy Slate
— Cliff Rocky Rhodes
William Bryant
— Major Doc Henry
Lynnette Mettey
John Carter
Jason Wingreen
Arch Whiting
Don Knight
— Dr. King
Sandy Kenyon
— Dr. Hart