The long-term results of open-heart valve surgery in Uppsala in the period 1959-1974 were reviewed. The total number of patients operated on was 677 and the mean follow-up time was 10 years (range 5-22 years). The operative mortality was high in the early years, but fell to 11-12% towards the end of the period. The main long-term complication was embolism. The frequency of late reoperation was 10-20%, reflecting the limited durability of the early mechanical valves and of subsequently used biologic valves. The actuarial 10-year survival, calculated as 50%, was approximately equal among the patients with aortic and those with mitral valve disease. The predominant late causes of death (60-75%) were 'cardiac', including myocardial as well as valve-related causes. Follow-up investigation comprised 244 survivors. In general there was considerable functional improvement both in the aortic and in the mitral group. Valvular insufficiency leading to reoperation was detected at follow-up examination in 6-8% of the patients.