During the period June 1989 to March 1991, laboratory evidence of sexually transmitted diseases (STDs) was found in 107 patients at the Red Cross War Memorial Children's Hospital in Cape Town. Data was available on 96 patients aged 23 months to 14 years (mean 75.9 months). Vaginal discharge was the most frequent presenting symptom (76%), particularly in those less than 5 years of age (90%). Although a history of abuse was not given on presentation in 62%, evidence of abuse was subsequently elicited in 67% of patients. Neisseria gonorrhoeae was the most common sexual pathogen (61 isolates, 8 penicillin resistant), followed by G vaginalis (17 isolates), Trichomonas vaginalis (7 infections), and T pallidum (9 TPHA positive, 5 with VDRL 1:4 or higher). Chlamydia trachomatis was demonstrated by immunofluorescence in 14 children. Multiple STDs were demonstrated in 10 patients. Although evidence of CSA was not found in all patients with STDs it was likely that the vast majority of patients had acquired these infections by CSA. Symptomatic prepubertal children with G vaginalis isolates should be investigated for CSA. Chlamydial immunofluorescence tests did not assist the diagnosis of CSA in children and should not be used, as they have no medicolegal significance.