Derek Teasdale was a consultant general surgeon in Rochdale. He was born on 11 February 1919, the eldest son of John Hall Teasdale, a house governor of Royal Waterloo Hospital, and Mabel Hannah Teasdale née Coldicott, a piano teacher. He attended Colfes School in Eltham and studied medicine at King’s College, London, qualifying in 1942. He was a house surgeon in Dorking, and then, in October 1942, was called up into the Navy, where he served as a surgeon lieutenant, including on the aircraft carrier HMS *Indomitable*. In 1943 he was seconded to naval hospitals in America. After the war, Derek returned to London to complete his surgical training. He was a senior house officer and then a registrar in general surgery at St James’ Hospital, Balham. From 1949 to 1953 he was a senior registrar at St James’ under Norman Tanner, from whom he developed his interest in upper abdominal surgery, which remained with him through the rest of his career. In 1953 he was appointed as a consultant to the Rochdale hospitals, a post he held until his retirement at 65. He wrote papers in the *British Journal of Surgery* (‘Colo-colic intussusception in the adult’ *Br J Surg* 1953 Sep;41[166]:128-32, ‘Concomitant rupture of the spleen and left kidney’ *Br J Surg* 1954 May;41[170]:620-2) and lectured, mainly on gastric surgery, at universities in the UK, Australia and Poland. Derek was chairman of Rochdale surgical unit associated with Highfield Nursing Home, which became the BMI’s prestigious Highfield Hospital. He was chairman of the Rochdale medical executive committee, and a member of Rochdale Health Authority. He was president of the surgical section of the Manchester Medical Society and, in 1980, of the Manchester Surgical Society. At the British Medical Association (BMA), he was president of the Rochdale division and on the BMA council and a member of the central committee of hospital medical services. He was elected as a fellow of the BMA in 1980. On retirement, Derek and his wife Betty (Elizabeth Eileen) née Edwards, who he met while he was in the Navy, moved to Dennington in Suffolk, where he continued his hobby of sailing. He also became involved in local politics. Later he moved to Mytchett in Surrey. Derek died on 21 October 2019 having celebrated his 100th birthday. Predeceased by his wife and son, Alex, he was survived by a daughter, Julia, and two granddaughters, Katherine and Eleanor.