Born on 1 June 1880 at Haverhill, Massachusetts, son of Thomas Lahey and Honora Frances Powers, he qualified in 1904 and served as intern at Boston City Hospital and Long Island Hospital 1904-05 and resident surgeon at Haymarket Square Relief Station in 1908. He became surgeon to the New England Baptist Hospital and the New England Deaconess Hospital. During the war of 1914-18 he served as a Major in the US Medical Corps and was chief of surgery in an evacuation hospital in France. He was a pioneer in thyroid surgery, and after the war was appointed Professor of Surgery at Harvard. He founded the Lahey Clinic in Boston in 1922, which had a definite obligation to the poor and needy as well as to the wealthy and distinguished. The Lahey Clinic has published regularly since 1938 a small *Bulletin* of high quality and a series of volumes of *Surgical practice* 1942, 1951 and 1962. Lahey was President of the American Medical Association in 1940, having served on its councils on Scientific Assembly from 1927 to 1937 and on Medical Education and Hospitals from 1938 to 1940. He was a member of the governing body of the American College of Surgeons, and a member of the Société de Chirurgie of Paris. During the war of 1939-45 he was chairman of the US National Commission for the procurement of medical personnel for the armed forces and consultant to the Medical Department of the US Navy, in which capacity he inspected many hospitals in the United States and the Pacific. He was awarded in 1946 the Bigelow medal of the Boston Surgical Society and the Friedenwald medal of the American Gastroenterological Association. Expert in thyroid, biliary and gastroenterological surgery, he was an inspiring teacher both at Harvard and at Tuft's College. In 1940 he was presented with a *Sixtieth Birthday Volume* contributed to by fifty-four writers. His leisure recreations were dog field trials and golf. In 1909 he married Alice Wilcox who survived him. He died on 28 June 1953 aged 73.