Jayston played Neville Badger in the 1989 television adaptation of David Nobbs's comedy of manners A Bit of a Do. He portrayed James Bond in a radio adaptation of You Only Live Twice in 1990. In 1991 he appeared as Colonel Mustard in the television series Cluedo and a year later made a guest appearance in the Press Gang episode "UnXpected". Other TV appearances include in EastEnders, Coronation Street, Only Fools and Horses, The Darling Buds of May, Tales of the Unexpected, The Bill and the character of Donald De Souza in Emmerdale. He also appeared in Holby City and Tracy Beaker Returns as Mr Spooner. Also appeared in Foyle's War.