His first major television role was in the sitcom "Doctor in the House" (1969–70), based on Richard Gordon's series of novels, which had already been turned into a feature film series. Evans starred as the young student doctor Michael Upton, to whom Evans felt he bore no similarities. Following the show's success he starred in the sequel to the series, "Doctor at Large" (1971). Evans enjoyed working with his fellow actors George Layton, Geoffrey Davies, Robin Nedwell and Richard O'Sullivan, and he later described these as the best years of his life. Work on the "Doctor" series was extremely intense and left him no time to take on other roles; he therefore declined to appear in the sequels. However, in a later interview he stated that he had been "incredibly stupid" to turn the series down.