From 1 January 1986 to 1 September 1989 124 women presented to the Ambrose King Centre (the department of genitourinary medicine of the London Hospital) alleging rape. Sexually transmitted diseases were found in 36 (29%) women (excluding candidosis and bacterial vaginosis). The commonest organisms detected were Neisseria gonorrhoeae and Trichomonas vaginalis, each being present in 15 patients. Eleven women had genital warts. Chlamydia trachomatis was isolated in six patients, two had herpes simplex virus infection and one patient had pediculosis pubis. Serological evidence of past hepatitis B infection was detected in five women and one patient had antibodies to human immunodeficiency virus. Eighteen of the 36 women (50%) had multiple infections. Six women had abnormal cervical cytology smears, three being suggestive of cervical intraepithelial neoplasia grades II-III. Although it is rarely possible to attribute infection to an assailant, these patients require further counselling, treatment and review. Rape victims are thus a population at risk of having sexually transmitted diseases and screening should be offered.