Born in Melbourne, he was the son of Herbert Eaton Daylesford Stevens, a pharmaceutical chemist, and Wynifred Blanche Beatrice Tod whose father came to Australia in 1860 during the Gold Rush. He was educated at Scotch College, Melbourne, and after graduation from Melbourne his first love was clinical pathology and he worked with the Commonwealth Serum Laboratories for two years. In 1941 he was appointed pathologist with the Commonwealth Health Department in Townsville.

In 1946 he made the important choice to become a physician, and after a year's study in Melbourne he gained his MRACP in 1947, followed by his MD in 1948. Frank maintained that the best thing that ever happened in his professional life was his admission to the College, for it opened up a new world for him. He moved to Launceston in private consultant practice and was appointed visiting honorary physician to the Launceston General Hospital in 1949. Here it was through his love of teaching and the high standards he set for himself, and which he also expected from others, that Frank exerted such a great influence on medical students, residents, registrars and colleagues. He encouraged many to sit for postgraduate examinations and many will largely attribute their success to his influence. Frank was at his best on a grand ward round or when demonstrating a patient of particular interest at a clinical meeting. Frank Stevens was an honorary assisting physician to the Queen Victoria Hospital (Obstetric).

An active member of the BMA and later the AMA he was heavily involved in the founding of the medical school at the University of Tasmania, and, largely through his influence, the Launceston General Hospital became involved in undergraduate training - a move which greatly enhanced that Institution. He was an active member of the Tasmanian Cancer Committee for many years and a member of the Tasmanian Tuberculosis Board.

He was a member of the standing committee on poliomyelitis and a member of the faculty of medicine, University of Tasmania. He was a member of the State Committee (Tas) of the College from 1960 to 1966, chairman from 1964 to 1966. Dr Stevens spent several years on the board of management of the Launceston General Hospital, those being days when doctors were able to exert influence at administration levels.

Frank's other love was gardening and he spent all his leisure time working amongst his beloved shrubs and trees, aerial grafting and hybridising scientifically. It was his joy to arrive at friends home and with pride to present a plant he had grown. Frank had two daughters Susan and Christine, in his first marriage. His second marriage to Norma, who shared his love for gardening, restored his happiness, and it was a bitter blow when two years before his own death he lost his loved partner. Soon after he became aware of his own fatal disease, but with characteristic and indomitable courage he fought back and was still working until a few days before his death. Frank left a considerable sum of money from his estate to the College to be used for postgraduate education - a typical final act from a man who loved his College and valued continual learning. Frank's brother, James Sydney Tod Stevens, was also a member of the College.