Since the start of the era of exclusive use of valve replacement in 1960, the only valve that has received continuous use [since 1962] has been the aortic homograft. Results with this valve indicate about a 60- to 70-percent 10-year survival rate. The next most continuously used designs have been the Smeloff-Cutter and the 1200-1260 series Starr-Edwards ball valves. Both of these valves have survival rates after 8 years of about 70%, and are, therefore, comparable to the homografts. More recently started series of homografts valves, tissue valves and prosthetic valves of various types appear to confer a better chance of 10-year survival than older valves in older series. Not all the improvements in survival rates can be ascribed to changes in valve design. Better selection of patients, improved intraoperative myocardial protection and better postoperative care all contribute to what appears to be progressive improvement in surgical results.