The porcine bioprosthetic valve has been in use at Henry Ford Hospital since 1971. In this review, 980 patients with 1,081 porcine bioprosthetic valves were examined from 1 month to 16.4 years after implantation with a 99% complete follow-up. Patient survival was 59% +/- 2.2% (+/- standard error of the mean) at 10 years and 38% +/- 4.0% at 15 years. Factors associated with decreased survival after hospital discharge were age greater than 35 years and New York Heart Association functional class IV. Freedom from thromboembolism was 92% +/- 1.2% at 10 years and 89% +/- 3.2% at 15 years. Freedom from endocarditis was 93% +/- 1.2% at 10 years and 92% +/- 1.3% at 15 years. Freedom from structural valve degeneration for all valves was 71% +/- 2.6% at 10 years and 31% +/- 5.6% at 15 years. Factors associated with increased risk of structural valve degeneration were age younger than 35 years, female sex, and preoperative cardiac index greater than 2 L/min/m2. Among a total of 172 patients undergoing removal of a degenerated valve, mortality was 12.5%, and significant risk factors for death at reoperation were emergency operation and functional class IV. Experience with the porcine bioprosthetic valve after 15 years suggests that its use be confined to older patients or patients with a contraindication of anticoagulation.