To assess the impact of cadaver donor age on posttransplant renal function and graft survival, we analyzed our clinical results in 17 recipients of younger donor kidneys (less than 10 years) and 48 recipients of older donor kidneys (greater than 50 years) and compared them with a control group of 598 patients who received kidneys from donors between 11 and 50 years of age. The 3 groups were comparable with respect to recipient age, duration of dialysis, prior transfusions, previous transplants, cold ischemia time, HLA AB mismatches, cytotoxic antibody profile, posttransplant ATN, and prophylactic ALG treatment. The cumulative patient survival at 1, 2, and 3 years was not significantly different among the 3 groups, but the graft survival in recipients of older donor kidneys was significantly lower than the control (71% vs. 62% at 2 years, P = .09 and 66% vs. 55% at 3 years, P = .0003. The short-term renal function assessed at 1 month posttransplant was significantly lower in the older donor group compared with the control (creatinine clearance 45 mL/min vs. 59 mL/min, P = .0003). Likewise, the long-term renal function assessed at the last follow-up was also lower in the older donor group than the control (creatinine clearance 40 mL/min vs. 49 mL/min, P = .07). There were no significant differences in graft survival or short- or long-term renal function between the younger donor group and the control group. These observations suggest that transplantation of a kidney from an older cadaver donor is associated with an inferior posttransplant outcome. The practical decision whether or not to use an older donor kidney should be individualized taking this as well as other factors into account.