Peter John Ryan was a pioneer in colorectal surgery. He was born, the eldest of four boys, on 25 November 1925 in Dookie, Victoria, Australia, to farming parents. He was dux of Assumption College, Kilmore, and then went on to study medicine at Melbourne University. He graduated in 1948 and was a resident medical officer at St Vincent's Hospital. From 1953 to 1954 he served as a Major in the Royal Australian Army Medical Corps in Japan and Korea, and then worked for a number of years in England. After obtaining his Fellowship of the College, he spent three years at Leicester General Hospital. Following his return to Australia in 1960, he joined the surgical staff at St Vincent's Hospital, Melbourne. In 1972, the Ryan unit was established, with Ryan as the inpatient surgeon. It later became the department of colon and rectal surgery, with Ryan as its first director. He retired from St Vincent's in 1990. His laboratory work included studies of the effects of a proximal colostomy on bowel anastomoses. In 1986, his Hunterian address to the College was on diverticular disease. He was the first to advocate immediate resection (with anastomosis) in selected cases of diverticular perforation. He was keen to share Australian surgical expertise with medical colleagues in Asia. From 1965 to 1966 he led a St Vincent's surgical team to Long Xuyen, in Vietnam. He also established a programme of visiting fellows from Japan and Indonesia, and lectured in Kuala Lumpur and Jakarta. He was the first honorary fellow of the Indonesian Surgical Association. Ryan was President of the International Society of University Colon and Rectal Surgeons from 1986 to 1988, and an original member of the Royal Australasian College of Surgeons' road trauma committee, which was responsible for the introduction of compulsory car seatbelts. His knowledge of anatomy and ability to sketch clearly made him a popular teacher. He was proud of his small red book entitled *A very short textbook of surgery* (third edition, London, Chapman & Hall Medical, 1994), which ran to several editions and was translated and widely used in China. He was an author of over 50 journal articles. In 1950 he married Margery Manly. They had 10 children, three of whom - Rowena, Jeremy and Roderick - followed him into medicine. He was awarded the medal of the Order of Australia in 2002, shortly before his death on 3 June 2002. The following is an amended version of this obituary, based on updated information. Peter Ryan was a consultant surgeon in Melbourne. He was born on 25 November 1925, in Shepparton, Victoria, the eldest of a farming family: his father was also Peter Ryan, his mother was Mona née McGuinness, a secretary and aspiring actress. From the Dookie State School, Peter went on to Assumption College in Kilmore, where he was *dux* in 1941. He studied medicine at Melbourne University, where he met Margery Manly, an arts student, whom he married in 1950. He was involved in theatre, writing, and the Newman and Campion societies, at one stage considering joining the Catholic commune, Whitlands. During his studies he contracted tuberculosis from a patient and took a year to recover. After qualifying, he did resident posts at St Vincent's Hospital. He passed the MS in 1953 and, partly to fund his future studies, joined the RAAMC and served in a field ambulance unit in Korea, where he averaged six operations a day, seven days a week. At the end of the Korean war he moved to London in 1954, passed the FRCS, and became registrar at Leicester General Hospital. On returning to Melbourne in 1957, he was appointed to St Vincent's, where he was a general surgeon, but gradually became more interested in colorectal surgery, receiving the Sir Alan Newton essay prize for a paper on diverticular disease. In 1965 St Vincent's asked Peter to organise civilian surgical teams to work in Vietnam. He led the first of these to Long Xuyen. He later learned that the cook and several of the other staff were Viet Cong. From then on he pioneered a programme for trainee surgeons from Indonesia and Japan, many of whom became firm friends. For this work he was honoured by being made the first honorary Fellow of the Indonesian Surgeons Association. In 1978 he set up a colorectal unit at St Vincent's and a few years later his own successful private service. He was one of the first to learn laparoscopic techniques, and to advocate resection and anastomosis in selected cases of perforation, for which he was awarded an Hunterian Professorship in 1986. He was President of the International Society of University Colon and Rectal Surgeons from 1987 to 1988. A prolific author of more than 50 research papers, Peter was a gifted teacher and produced a popular work *A very small textbook of surgery* (London, Chapman & Hall Medical, 1988) which was translated into Mandarin and Indonesian. In 1996, the Peter Ryan prize in surgery for final year students was established in his honour. He and his wife had 10 children, 3 of whom - Rowena, Jeremy and Roderick - followed him into medicine. He was awarded the medal of the Order of Australia in 2002, shortly before his death on 3 June 2002.