To determine the incidence, prevalence, and prognostic value of preoperative and postoperative renal dysfunction occurring in adults undergoing orthotopic liver transplantation, the records of 102 consecutive adults who underwent orthotopic liver transplantation using cyclosporin A were reviewed. Renal dysfunction was defined arbitrarily as an increase in creatinine or blood urea nitrogen, or both, to 1.5 and 50 mg/dl, respectively, in patients previously having normal renal function or a 50% increase in either creatinine or blood urea nitrogen in patients with preexisting renal dysfunction. Twenty-six of the 102 patients had renal dysfunction before orthotopic liver transplantation. Sixty-eight of the 102 patients studied experienced an episode of renal impairment after orthotopic liver transplantation. Forty-nine of these episodes developed early, having occurred within the first 6 days. Late renal impairment occurred in 36 cases at 32 +/- 6 days after orthotopic liver transplantation. Using multivariate analysis, cirrhosis of a noncholestatic nature was found to be an independent predictor of early renal impairment. Trough blood cyclosporin A levels measured by radioimmunoassay were higher in those who experienced early renal impairment or late renal impairment than in those who did not (p less than 0.05). Several factors capable of adversely influencing renal function (nephrotoxic drugs, shock, and graft failure) other than cyclosporin A were present also in half of the patients who developed late renal impairment. Overall, 25 patients died. Multivariate analyses identified serious postoperative infection, graft failure, and preoperative renal dysfunction to be independent predictors of mortality.