After training at adult drama classes in Nottingham, he gained a place at RADA, graduating in 1968. His first starring role, also for Granada Television, was in The Lovers which was created by Jack Rosenthal and co-written with Geoffrey Lancashire and ran from 1970 to 1971. He also made a small appearance in the John Finch-created series A Family at War in 1970.
From 1974 to 1977 he starred in two of Britain's most popular comedy programmes at the same time: Rising Damp and Porridge, as well as the latter's spin-off Going Straight, becoming a household name in the process. His other parts included Armchair Theatre, The Rivals of Sherlock Holmes and the film versions of The Lovers and Porridge.
The entertainment profession was stunned when Beckinsale died in his sleep from a heart attack caused by an undiagnosed congenital heart defect at the age of 31. His daughter Samantha Beckinsale also appeared in Coronation Street in November 1996 when she played Lorraine Mason, a friend of Raquel Watts in three episodes.