Despite the absence of sophisticated thoracic surgical facilities, valuable relief was provided to young patients with progressive symptoms of rheumatic mitral stenosis in Zaria (Nigeria) whose response to the medical regime had been unsatisfactory. Using digital trans-atrial commissurotomy, which is technically straightforward and involves little blood loss and no elaborate surgical equipment 18 patients with a lone mitral stenosis were symptomatically improved but three with mixed mitral stenosis and regurgitation died. There is urgent need to reduce the prevalence of rheumatic fever in this and other parts of the tropics.