He has appeared in three science fiction programmes — as the second actor to portray Travis in Blake's 7 and also as Borg in the Doctor Who story The Robots of Death. He also appeared in the Doctor Who spin-off Shakedown: Return of the Sontarans. Earlier, in 1973, he played a key protagonist in the children's adventure series The Jensen Code.
In 1978, he played a major role opposite Tom Bell in the Thames Television/Euston Films thriller series Out.
He also played the role of Rooky in the Southern Television series, The Famous Five, in the double episodes of Five Get Into Trouble.
One of his earliest film roles was in the Carol Reed's film musical of Lionel Bart's Oliver!, he played one of the London Bridge bargemen - a small uncredited speaking part. His other film roles included Burke & Hare (1971), the 1972 film Made (1972) starring Carol White, the comedy short The Waterloo Bridge Handicap (1978), A Nightingale Sang in Berkeley Square (1979), Deadly Game (1982), Scrubbers (1983) and Underworld (1985).
He also appeared as a "Pay Cop" Lieutenant in the ITV serial Quatermass, starring Sir John Mills which was broadcast in the UK in 1979. As "Big John" in Monday Night Fever, the ninth epidode of the first series of Minder. He was also in the 1985 drama serial Edge of Darkness, playing the chief of security Connors.
He appeared in the episode "Parade" in the second season of Bottom as "Ted Nugent" who Eddie calls "Harry the Bastard".
He also appeared in a supporting role in the Clive Owen film I'll Sleep When I'm Dead. He is currently appearing in a TV commercial for Aviva insurance. He has directed 2 short films Rank (2009) co-written with Nick Wilkinson, and Vodka & Coke (2013), also written and produced by Nick Wilkinson.
In 2012, he acted the character of Lonnie in the feature film Coolio (C.O.O.L.I.O – Change Original Ordinary Lives Interface Oracle), which was released in 2014.
He now lives in Kent with his wife and two children.
Other TV appearances include: Grange Hill, Public Eye, Callan, Dixon of Dock Green, Softly, Softly: Taskforce, Villains, Six Days of Justice, Warship, The New Avengers, The XYY Man, Shoestring, Minder, The Gentle Touch, The Professionals, The Chinese Detective, The Young Ones, Dempsey and Makepeace, C.A.T.S. Eyes, Rockliffe's Babies, Bread, Lovejoy, Wycliffe, Casualty, The Bill, Doctors and New Tricks.
Brian Croucher is a patron of The Music Hall Guild of Great Britain and America.