The objective of this study was to evaluate estimated and measured donor renal function in predicting graft function long-term and to identify donor criteria associated with nonacceptable graft prognosis. In 200 consecutive cadaver donors creatinine clearance was measured at explantation and estimated using the Cockcroft formula on admission serum creatinine. Graft function was evaluated in recipients (n = 387) by 24-h creatinine clearance regularly during 3 years after transplantation. Measured creatinine clearance correlated to some extent with long-term graft function, while Cockcroft estimation was slightly superior and similar to using donor age only. Kidneys from donors with intra-operative creatinine clearance < or = 55 mL/min (median 50 mL/min) produced acceptable recipient graft function of 48 mL/min at 3 years and 76% 3-year graft survival. Donor age > or =60 years resulted in clearance at 3 years of 29 mL/min and 78% 3-year graft survival; adding the criteria of admission Cockcroft < or =60 mL/min, graft function at 3 years (28 mL/min) and 3-year graft survival (76%) were similar. In conclusion, creatinine-based estimates of the functional capacity of the donor kidney, calculated or intra-operatively measured, do little to improve the ability of donor age alone to predict long-term allograft function after renal transplantation, and nonacceptable donors are not discriminated.