MRCS LRCP 1943; MB ChB Manch 1943; FRCS Edin 1947; FRCS Eng 1955.
Gregory was born in Manchester on 4 July 1917, he was educated at South Manchester Grammar School and the University of Manchester. After qualifying, Gregory was house surgeon at Preston Royal Infirmary. He served in the RAMC before being appointed surgical registrar at MRI, where he was later supernumary chief assistant to the professorial unit. In 1947 Gregory was appointed resident surgical officer at Bolton Royal Infirmary, and the next year surgical registrar to Withington Hospital Manchester. From 1950 until 1955 Gregory was senior registrar to Kent and Sussex Hospital and also to Guy's Hospital before working at St Peter's Hospital, London. Gregory later worked in Rhodesia and Libya.