We evaluated the 80 cases of porcine valve replacement, accomplished between April 1975 and December 1980. There were 48 males and 32 females aged between 16 and 60 years old with a mean of 37.4 +/- 11.4. Ten patients underwent aortic valve replacement (AVR), 63 mitral valve (MVR), and 7 AVR plus MVR. Twenty-seven Hancock valves (H) were implanted in aortic (3) and mitral (24) position and 61 Carpentier-Edwards valves (CE) were used in aortic (14), mitral (46), and tricuspid (1) position. The mean duration of follow-up was 9.3 years (0.2-19.2 years) and cumulative follow-up was 747.2 patient years (py). The late mortality was 3.3%/py (25 patients). Actuarial survival rates for all patients at 10 and 15 years were 67%, and 49% respectively. The linearized rates (LR) of structural valve deterioration (SVD) was 7.0%/py. The freedom from SVD for all patients at 10, and 15 years were 47.1%, and 12.4% respectively. There were no differences of free rates of SVD between H and CE. between valve sites implated, and among age at operation. The incidence of occurrence of SVD was gradually increased 6 years after operation. The LR of thromboembolism (TE), anticoagulant-related hemorrhage (ACH), prosthetic valve endocarditis (PVE), nonfunctional valve dysfunction (NVD), and reoperation (RO) were 0.7%/py, 0.1%/py, 0.3%/py, 0.1%/py and 7.4%/py, respectively. The freedom from TE, ACH, PVE, NVD, and RO for all patients at 15 years were 91.3%, 98.1%, 95.6%, 80%, and 6.5%, respectively. The surgical results of glutaraldehyde-preserved porcine bioprostheses was excellent during the first 5 years after operation. A high incidence of SVD has been occurred thereafter. According the indication for valve replacement with bioprotheses is now strictly limited for elderly, child bearing female case, contraindition for therapy of anticoagulants, and some social condition.