- James Coburn
- Professor Robert Elliot
- Lee Grant
- Jean Robertson
- Harry Andrews
- Bert Parsons
- Ian Hendry
- Alex Hellman
- Michael Jayston
- David Baker
- Christiane Krüger
- Christina Larsson
- Keenan Wynn
- E. J. Farnsworth
- Terence Alexander
- Business Tycoon
- Philip Anthony
- Eliot's Secretary
- Julian Glover
- Arnold Pryce-Jones
- Mary Larkin
- Betty - Jean's Secretary
- Ewan Roberts
- Laboratory Technician
- David Swift
- Chester Drake
- Rolf Wanka
- Art Dealer
- Ray Callaghan
- TV Producer
- Ralph Ball
- Boy Friend
- Susan Majolier
- Laboratory Assistant
- Brian Tully
- First Business Man
- Michael Nightingale
- Second Business Man
- Carrie Kirstein
- Margaret - the Air Hostess
- Richard Cornish
- Co-Pilot
- Geoffrey Burridge
- Floor manager
- Victor Harrington
- Guest at Farnsworth's Reception
- Richard Marner
- German Delegate
- Judy Robinson
- Production assistant
- Kevin Scott
- Maxwell
- Robert Tayman
- Mixer
- Reg Thomason
- Guest at Farnsworth's Party
