Robert Maclaren was born in Glasgow on 27 October 1923 and was educated at Glasgow Academy. His preclinical medical education was at King's College, London, before qualifying from the Westminster Hospital. After two years of resident appointments at the Westminster and Royal National Orthopaedic Hospitals, he served in the RAF from 1948 to 1950 before taking the FRCS. On demobilization he spent two years as a registrar in radiotherapy at Westminster Hospital during which time he completed the DMRT. In 1954 he was appointed radiotherapist to the Ontario Cancer Treatment and Research Foundation at the Hamilton Clinic where he made important contributions during the next 25 years. In 1977 he became acting director of the Ontario Cancer Foundation and was appointed head of the department of radiotherapy at the Hamilton Clinic in 1978. He also served on the staff of the Hamilton Civic Hospitals, McMaster University Medical Centre, St Joseph's Hospital and Chedoke Hospital. Maclaren had a notable capacity for hard work and an intuitive sympathy which contributed greatly to his compassionate care of patients. His interests outside his medical work were wide and he was a founder member of the Bruce Trail Association in 1961. He was also a member of the Wild Life Advisory Board of the Hamilton Region Conservation Authority. He published a number of papers concerning cancer of the lip, the ovary and the rectum, and on the use of adjuvant chemotherapy. He died on January 28 1980 as a result of multiple injuries sustained in a road traffic accident. He was survived by his wife, Gertraut, daughter Gretal and two sons, Robert and Peter.