When acute hepatitis B developed in 3 patients who had had gynaecological surgery, the surgeon was found to be a carrier of hepatitis B e antigen. Of 268 patients operated on by this surgeon in one hospital, 247 were screened for markers of recent or current hepatitis B. 22 (9%) had such markers, associated with symptoms in 5. The operations carrying greatest risk of infection were hysterectomy (10/42) and caesarean section (10/51). These findings strengthen the case for vaccination of all surgeons and medical students against hepatitis B.