Ralph Francis Phillips was born in London on 8 May 1903 the son of Lorraine Phillips, a printer, and Emma, née Kerrison. At the age of ten he went to Christ's Hospital, where he remained for nine years until he entered St Bartholomew's Hospital Medical School. There he won the junior scholarship in 1923, the senior scholarship in 1925, the Brackenbury scholarship in surgery in 1927 and later as a post-graduate the Luther Holden research scholarship in surgery in 1930. He qualified in 1927 and after junior appointments passed the London MS in 1930 and the FRCS two years later. Although he had intended to pursue a career in surgery, his interest was particularly in the treatment of malignant disease and he joined the department of radiotherapy at St Bartholomew's as chief assistant from 1932 to 1940. He passed the DMRE a year after joining the department, working under Dr Neville S Finzi, who had been in charge since 1912 and who had pioneered treatment with mega-voltage irradiation. As early as 1938 he was able to demonstrate its value in producing complete regression of an inoperable rectal carcinoma in a patient who survived for over twenty years. At the outbreak of war he was placed in charge of the radiotherapy department and was the sole radiotherapist running both the deep x-ray and supervoltage departments. Despite a heavy workload he was able to write Supervoltage x-ray therapy, in conjunction with George Innes, which was published in 1944 and was widely acclaimed on both sides of the Atlantic. It attracted the attention of the distinguished American, James Ewing (of Ewing's tumour) who had met Ralph Phillips before the war and was determined to secure his services for the Memorial Hospital in New York. He started work there as attending radiotherapist in 1945 but shortly after his arrival suffered a serious recurrence of pulmonary tuberculosis, success-fully treated with streptomycin which had then just become available in the United States. He soon resumed his work especially in the treatment of bone tunours and childhood cancer with megavoltage therapy. He was elected Hunterian Professor in 1952, giving a lecture on the treatment of neuroblastoma and in the same year was appointed Professor of Radiation Therapy at Cornell University, New York, and later departmental chairman at Memorial-Sloane Kettering. His retirement in 1968 was marked by an international symposium in his honour. After retirement he continued to live at Mendham, New Jersey, with his wife, Barbara whom he had married in 1932. His only son Paul graduated MD from Albany University and became Professor of Medicine at Syracuse University, New York. He died at his home in Mendham on 17 July 1989 aged 86 years.