Benjamin was educated at the University of Glasgow and at St Bartholomew's Hospital - entering as a student in 1911, he graduated M.B., B.Ch. in 1913. He was honorary medical registrar at the New Somerset Hospital, Cape Town, and additional medical officer and anaesthetist to the Free Dispensary in Cape Town. Benjamin gained a temporary commission in the R.A.M.C. at the rank of Lieutenant on 6th November 1916 and entered the war in France on the 27th December. He was the son of Mrs A Levitan of 31 Mill Street Gardens, Cape Town, South Africa.