- Writer:
- Nigel Kneale
- Producer:
- Rudolph Cartier
- Special Effects (Sound):
- BBC Radiophonic Workshop
- Special Effects (Vision):
- Jack Kine
- Special Effects (vision):
- Bernard Wilkie
- Film Cameraman:
- A.A. Englander, F.R.P.S.
- Film Editor:
- Ian Callaway
- Telerecording Editor:
- Sheila Tomlinson
- Music composed by:
- Trevor Duncan
- Designer:
- Clifford Hatts
- Dr. Matthew Roney:
- Cec Linder
- Barbara Judd:
- Christine Finn
- Professor Quatermass:
- Andre Morell
- Colonel Breen:
- Anthony Bushell
- Private Secretary to the Minister:
- Richard Dare
- The Minister:
- Robert Percival
- Captain Potter:
- John Stratton
- Police Inspector:
- Ian Ainsley
- Sergeant:
- Michael Ripper
- Corporal Gibson:
- Harold Goodwin
- Private West:
- John Walker
- P.C. Ellis:
- Victor Platt
- Young Constable:
- Kenneth Warren
- Mrs. Chilcot:
- Hilda Barry
- Miss Groome:
- Madge Brindley
- News Editor:
- Tony Quinn
- James Fullalove:
- Brian Worth
- Sladden:
- Richard Shaw
- Others taking part:
- Keith Banks
- Others taking part:
- Michael Bird
- Others taking part:
- Van Boolen
- Others taking part:
- Janet Burnell
- Others taking part:
- Anne Bushell
- Others taking part:
- Patrick Connor
- Others taking part:
- Clifford Cox
- Others taking part:
- Frank Crane
- Others taking part:
- Brian Gilmar
- Others taking part:
- Arthur Hewlett
- Others taking part:
- Janet Joye
- Others taking part:
- Tony Lyon
- Others taking part:
- Donald McCollum
- Others taking part:
- John Rae
- Others taking part:
- Michael Raghan
