While studying medicine, Miller was involved in the Cambridge Footlights, appearing in the revues "Out of the Blue" (1954) and "Between the Lines" (1955). Good reviews for these shows, and for Miller's performances in particular, led to his performing on a number of radio and television shows while continuing his studies; these included appearances on "Saturday Night on the Light", "Tonight" and "Sunday Night at the London Palladium". He qualified as a physician in 1959 and then worked as a hospital house officer for two years, including at the Central Middlesex Hospital as house physician for gastroenterologist Francis Avery Jones.