Three years ago I was invited to start a course in human sexuality at St George's Hospital Medical School with the support of the Nuffield Foundation. It was based on my four previous years of experience teaching this subject in the USA at the University of Pennsylvania Medical School. The original course at St George's consisted of one whole-day and 11 two-hour sessions, given at weekly intervals for 15 fifth-year medical students during their obstetrics and gynaecology or psychiatry rotation (Stanley 1977).