One hundred fifty-five freeze-dried, 63 frozen, and 337 Hanks'-antibiotic solution preserved or nutrient-antibiotic solution preserved homografts used for isolated aortic valve replacement have been followed for 1 to 20 years (mean, 5.3 years), a total of 2,931 patient-years of follow-up information. Overall survival, valve-related death, primary tissue failure, failure due to surgical technical error, infective endocarditis, and overall event-free survival have been assessed and compared. Overall survival 20 years after operation was 51.6% +/- 8.1% with a low incidence of sudden death. The method and length of preservation did not have any effect on the long-term performance or the mode of failure of the homografts. The rate of primary tissue failure was apparently higher with valves preserved in a solution containing calf serum, but the difference was not significant. It is concluded that long-term patient survival and quality of life after aortic valve replacement with a homograft are excellent. The current study, however, could not verify the existence of a significant difference between the three assessed methods of homograft preservation. Furthermore, it could not prove the importance of cellular viability or the existence of clinically significant immunological factors other than the calf serum content of the nutrient medium.