Osler Dickinson, the first of nine children of a Canadian farmer, was born at Hope, Ontario, on 29 September, 1908. There are no physicians recorded in the previous family history so the parents' choice of first name for their oldest child was probably not in hopeful anticipation of his eventual profession, indeed the family had farmed that land for more than a century. After elementary and high school education in Port Hope, Dickinson entered Queen's University, Kingston, he was recipient of the Hoffmann Fellowship for surgery in 1934 and graduated in the following year. Following internships at St Joseph's Hospital, Toronto, and Lincoln Hospital, New York, he came to England to do further resident jobs at Grimsby Seamen's Hospital, the Evelina Hospital for Sick Children and St Andrew's Hospital, Bow. He then became a resident at St Mark's Hospital and later expressed his indebtedness to the late W B Gabriel there. After taking the Final Fellowship examination here he returned to Canada about the end of the second world war and then became FRCSC in general surgery and a member of the College of Physicians and Surgeons of the Province of Ontario. From 1950 to 1956 Dickinson practised general surgery at Trenton General Hospital, Ontario, and then moved to Scarborough, Toronto, where he undertook general surgery with an emphasis on proctology and also did some general practice. He was historian of Durham County, Ontario, and wrote many original articles concerning its history. He was a member of the Royal Canadian Institute and of the Ontario History Society, a freemason from 1937 and a member of the Canadian Masonic Research Association. Dickinson married Dr Liane Bloch, herself a medical graduate of Prague University, on 14 April 1949 and she retired from medical practice after their marriage. They had no children and he died on 6 October, 1977, survived by his wife.