Bert Coules worked in radio drama for ten years, gaining experience as a recording engineer, sound-effects technician, script reader and producer-director before becoming a full-time writer in 1989.

Coules began writing without any previous training, saying that he only heard a bad radio drama and felt he could do better. He wrote his first script in 1977 and had it accepted, a 45 minute docu-drama called "Wagner in Hell".

Coules specializes in science fiction and mystery audio and radio drama, and has written a number of adaptations, most notably the Sherlock Holmes radio series starring Clive Merrison as Holmes and Michael Williams/Andrew Sachs as Watson. He also produced original scripts for this series, which was also issued on CD. He has also written adaptations of several of Ellis Peters' Brother Cadfael novels, starring Philip Madoc as Cadfael, and of works by Ian Rankin, Val McDermid, Isaac Asimov and other best-selling genre authors. He is an avowed Arthur Conan Doyle and Doctor Who fan.

Original pieces include:

• The Further Adventures of Sherlock Holmes (four series) starring Clive Merrison and Andrew Sachs
• Fear on Four: The Man in Black (three episodes)
• A Magician Amongst the Spirits: the deaths and lives of Harry Houdini

Dramatisations include:

• Flowers for Algernon: The Radio Play, starring Tom Courteney
• A Wizard of Earthsea, starring Michael Maloney and Judi Dench
• The Thirty-Nine Steps, starring David Robb and Tom Baker
• The Three Hostages, starring David Robb, Haydn Gwynne, Michael Malone and Clive Merrison
• Mr Standfast, starring David Robb, Clive Merrison, Struan Rodger, Jasmine Hyde and Jon Glover
• Mutiny on the Bounty, starring Oliver Reed and Roger Daltrey
• The BBC's complete Sherlock Holmes - all four novels: A Study in Scarlet, The Sign of the Four, The Valley of Fear and The Hound of the Baskervilles, and twenty-four of the short stories, starring Clive Merrison as Holmes and Michael Williams as Watson.
• Rebus: Resurrection Men
• Rebus: The Falls
• Brother Cadfael: Monk's Hood
• Brother Cadfael: The Virgin in the Ice
• Brother Cadfael: Dead Man's Ransom
• The Guns of Navarone, starring Toby Stephens

In 2008 Coules appeared in a television documentary titled Decoding Cadfael which detailed the process of producing the series.