Clinical results with the xenograft cardiac valves were reviewed for 212 patients who underwent heart valve replacement from January 1981 to December 1987. One hundred and twenty-four Carpentier-Edwards k 88 Ionescu Shiley valves were used. Overall operative mortality was 11 out of 212[5.1%]: 5 out of 153[3.39o] for mitral valve replacement [MVR], 2 out of 34[5.9%] for aortic valve replacement [AVR], 0 out of 4[0%] for Tricuspid valve replacement [TVR], and 4 out of 21[19.1%] for double valve replacement [DVR;MVR+ AVR]. Two hundred and one operative survivors were followed up for a total of 824.3 patient-years [a mean 3.9*1.8 yrs], and the follow up was 78.1%. The linealized complication rates were 0.1% emboli / patient-year, 1.0% endocarditis/ patient-year and 2.2% overall valve failure / patient-year. A linealized rate of primary tissue failure was 0.7*/o/ patient-year. The actuarial survival rates including the operative mortality were 92*2.8% at 4 years and 85*4.3% at 7 years after surgery using the Xenograft cardiac valves. Probabilities of freedom from thromboembolism and overall valve failure were 73*11.0% and 69*2.4% at 7 years after surgery using the Xenograft cardiac valves respectively. The intrinsic durability of the Xenograft cardiac valves appears to be relatively well satisfactory over the long term [4 to 7 years] and the risk of failure appears well balanced by the advantages of a low incidence of thromboembolism and no mandatory anticoagulant therapy.