The objective of this study was to determine the impact of pretransplant renal function on graft and patient survival rates after orthotopic liver transplantation (OLT) using the United Network for Organ Sharing (UNOS) database for adults who underwent OLT between 1988 and 1996. Based on calculated creatinine clearance (CCr) at the time of OLT, patients were classified arbitrarily into those with normal renal function (>70 mL/min) and mild (40-69.9 mL/min), moderate (20-39.9 mL/min), and severe (<20 mL/min) renal insufficiency. Of the 20,281 patients who underwent transplantation, complete data were available for 19,261 patients. Of these, 12,778 (67%) had normal CCr (mean, 118 +/- 50 mL/min) and 4,419 (22%) had mild (56 +/- 8.5 mL/min), 1,560 (8%) had moderate (30 +/- 5.7 mL/min), and 504 (3%) had severe (14 +/- 3.6 mL/min) renal failure. UNOS status 1 was more common in patients with moderate and severe renal failure. Primary graft nonfunction and 30-day mortality rates were higher and 1-, 2-, and 5-year graft and patient survival rates were lower in patients with moderate or severe renal failure. Multiple regression analysis showed that renal failure was an independent predictor of 30-day and 2-year mortality after adjusting for the recipient's age, sex, etiology of liver disease, diabetes status, body mass index, cold ischemic time, and UNOS status. CCr less than 40 mL/min was associated with significantly lower short-term and long-term graft and patient survival rates. In conclusion, our findings suggest that when Mayo End-Stage Liver Disease (MELD) score is used to prioritize organ allocation, lower-than-expected graft and patient survival rates may be seen.