The authors have made a retrospective study of the case notes of 200 patients with valvular disorders seen over the course of 35 months (excluding those due to constrictive endocardial fibrosis). The cases represent the frequency of cardiac failure, especially in the mitral group. The authors found 61% to have mitral valve disease, 28.5% aortic valve disease, and 9.5% disease of more than one valve. Mitral valve lesions were found most frequently in young females (average age 26 years); aortic valve lesions were found more commonly in an older age group of men (average age 47 years). The authors discuss the aetiology. Rheumatic fever was responsible in 60% of cases, and caused particularly mitral valve disease. Atherosclerosis and syphilis were the commonest causes in the aortic group. Indications for surgery were found in 74 cases (37%), and 28% of these were closed heart techniques. The course of the disease is best appreciated during the first hospital admission. The mortality rate was 5.5%, and most of the patients (65%) were stabilised on treatment.