The prevalence of HIV infection in East Africa has increased rapidly in recent years. We made a prospective study of the incidence of HIV-seropositivity in patients undergoing orthopaedic procedures in a large district hospital in Bulawayo, Zimbabwe. One of our aims was to determine whether a clinically-based screening programme, derived from the Centre for Disease Control classification of HIV infection, could identify high-risk individuals before surgery. During a 3-month period, 76 patients were tested, and 12 were HIV-positive (16%). Only two of these patients (17%) had clinical features associated with HIV infection; ten (83%) were entirely asymptomatic. Our results indicate that preoperative clinical screening is unlikely to be successful in identifying seropositive patients before routine surgery.