John Gerald Callanan was born in Ennis, County Clare, on 21 June 1920, the son of John Callanan, a British Government Official, and his wife, Margaret. He spent his early years in England, returning for schooling to Mount Mellory where he attended the veterinary college for a while before transferring to medicine. He qualified in 1946 from the National University of Ireland and initially pursued a thoracic surgical career. He became surgical registrar at the London Chest Hospital, publishing an article on modified thoracoplasty with Thomas Holmes Sellors as a co-author. In 1955 he emigrated to the United States first becoming a resident at Bellevue Hospital, New York, but later moving to San Francisco where he practised general surgery for almost thirty years before he retired. For many years he was editor of the *San Francisco medical bulletin*. John Callanan was a keen traveller and an outstanding conversationalist who had wide intellectual interests. He was wintering on the Costa del Sol, Spain, when he died suddenly of a myorcardial infarction on 24 February 1985. He was survived by his wife, Irene, a Dublin girl whom he had met in New York at a party given by the Irish representative of the United Nations. There were no children.