Lloyd Nyhus was the first Warren Cole professor and head of surgery, and the second academic surgeon, at the University of Illinois, Chicago. During his 22 years as head of the department, Nyhus developed innovative, multidisciplinary residency programmes for more than 300 doctors and recruited top-flight doctors and scientists to the department. He was part of a recognised generation of academic surgeons with national and international acclaim, and managed to foster relationships with students, residents, staff and colleagues worldwide. With a kind and calm disposition and an innate sense of humour, he was a mentor and role model to a generation of outstanding surgeons. He was born on 24 June 1923 in Mount Vernon, Washington, USA, the son of a Lutheran principal. Lloyd's subsequent interest in science and medicine were merely an extension of the caring and nurturing philosophy of his parents. After graduating in 1947 from the University of Alabama College of Medicine at Birmingham, he was fortunate to receive his surgical training in Seattle, Washington, under the tutelage of Henry N Harkins. Harkins had a profound effect on Lloyd Nyhus, whose subsequent career mirrored and built on that of his mentor. After finishing his surgical training in 1956 he served in the US Naval Reserve Medical Corps and then returned to the University of Washington, Seattle, in a productive scientific and clinical career until 1967, when he was recruited to the University of Illinois department of surgery. The Seattle ulcer group, led by Harkins and Nyhus, became well known for their studies on peptic ulcer surgery. Over a 15-year period their work helped to define the operation of vagotomy and antrectomy as the 'gold standard' by which duodenal ulcer treatments were judged, certainly in the USA. In these years they published their landmark textbook *Surgery of the stomach and duodenum* (London, J & A Churchill, 1962), detailing the physiological and clinical factors which had influenced the development of gastric surgery. Prominent among the many topics investigated were burns, disorders of the digestive tract and hernias. Lloyd Nyhus published more than 370 scientific papers in refereed medical and surgical journals, edited in English and foreign translations, and wrote 133 textbook chapters in surgery. His other textbooks, *Mastery of surgery* (Boston, Mass, Little, Brown, 1984) and *Hernia* (Philadelphia, Pitman Medical Publishing Co/J B Lippincott, 1964), in addition to *Surgery of the stomach and duodenum*, persist in updated editions with new editors, and so continue to educate and influence new surgeons worldwide. In 1968 he established a transplant surgery unit at the Chicago school, making it the first large medical institution in the area to commit to human heart transplantations. He was well known for having his residents 'on parade' at 6.30 am, after performing their own rounds. They would be required to discuss each patient's status, and he would instinctively be aware if any detail had been missed out. In surgical procedures he insisted on trainees following the techniques he taught, and his students 'had to put a suture within a millimetre of where he instructed them', so related Donald Wood, an associate professor of surgical oncology, who had studied under Nyhus in the early 1970s. He served on the editorial boards of many surgical journals, including as a senior member of the board of *Hernia*, an excellent and growing journal. He was heavily involved in numerous professional organisations, spending terms as chairman of the American Board of Surgery, as president of the Central Surgical Association, the International Society of Surgery, the Chicago Surgical Society, the Society of University Surgeons, the Society for Surgery of the Alimentary Tract, the Illinois Surgical Society and the Warren H Cole Society. He was first vice president of the American College of Surgeons and of the American Surgical Association. Lloyd Milton Nyhus died peacefully at the age of 85 years from natural causes on 15 December 2008 in a Glenview nursing home. Predeceased by his wife, Margaret, in 2006, he left a son, Leif, a daughter, Sheila Massey, and two grandchildren. A memorial service to commemorate his life and works was held at Ascension Lutheran Church, Northfield, Illinois. A fund was set up to support an annual Lloyd M Nyhus memorial lecture in surgery.