To investigate the impact of donor age on the immediate and long-term graft outcome, 808 primary cadaveric renal allograft recipients, transplanted between January 1983 and December 1992, were divided into six groups according to donor age: 10-19 years (n = 142), 20-29 years (n = 214), 30-39 years (n = 136), 40-49 years (n = 146), 50-59 years (n = 142), 60-69 years (n = 28). The six groups were comparable with regard to donor origin (local/distant), serum creatinine, cold ischemia and reanastomosis time, recipient sex, degree of presensitization, number of pretransplant blood transfusions, number of HLA-B and B/DR mismatches. The incidence of delayed graft function was linearly correlated with increasing donor age, from 11.9% (donors 10-19 years) to 39.3% (donors 60-69 years) (P<0.0001). Graft survival at 3 years was not influenced by donor age (from 89.3% for the youngest donors to 84.4% for donors 60-69 years). After the 3rd decade, the creatinine clearance linearly decreased with donor age (6.2 ml/min, P < 0.01). This progressive decline could not be attributed to the recipient age (-7 ml/decade for 485 recipients < 50 years, and -6.1 ml/decade for 323 patients > or = 50 years). Despite the decreased function in older kidneys, recipient renal function remained remarkably stable between 1 and 3 years after transplantation within each donor age group.