Of 631 renal allografts performed at our center between January 1, 1979 and June 30, 1989, 368 were from cadaver donors (CAD) and 263 were from living-related donors (LRD). The recipients were almost equally divided among 3 ethnic groups: Black, Hispanic, and non-Hispanic, non-Black (primarily of northern European background). Recipient ages ranged between 1 and 70 years. In the CAD group HLA matching was emphasized so that no patient received a kidney with less than a 1 DR match, and for the entire series there was a mean of 2.4 of 6 HLA antigens matched between donor and recipient. All patients (LRD and CAD) received at least 3 pretransplant blood transfusions. Overall actuarial 10-year patient and graft survival were 68% and 48% respectively, with 72% patient and 56% graft survival for LRD and 58% patient and 36% graft survival for CAD recipients. Factors adversely affecting long-term graft outcome were: a) Black race. Overall 10-year graft survival was 23% versus 55% for non-Blacks (p = 0.008); b) Type I Diabetes before transplant. Overall 10-year graft survival was 35% versus 51% for nondiabetics; and c) Compliance. This was the most significant factor influencing long-term survival, other than death due to cardiovascular disease. In a non-Black, nondiabetic category of less than 36 years of age at transplantation (n = 169), 10-year patient survival in LRD and CAD groups was 95% and 85%, respectively, and graft survival was 78% and 70%, respectively. This was markedly different from the entire series (p = 0.008). Even in this group, 4 of the 17 graft losses (including mortality) were due to documented prolonged noncompliance in teenagers. The 6 other deaths that occurred were due to hepatitis/cirrhosis (2), CMV (3), and AIDS (1). Among the factors not influencing graft survival in the CAD group was HLA matching after the minimum requirements were fulfilled, either by comparing 1 with 2 DR antigens, or total HLA (1-6) antigens matched.