BACKGROUND Acute renal failure (ARF) is a common complication after liver transplantation (LTx). Identification of risk factors may prevent the development and attenuate the impact of ARF on patients outcome after LTX. METHODS Retrospective analysis of variables in the pre, intra, and postoperative periods of 92 patients submitted to LTx was performed in order to identify risk factors for development of ARF after LTx. ARF was defined as serum creatinine > or = 2.0 mg/dL in the first 30 days after LTx. Univariate and multivariate analysis by logistic regression were performed. RESULTS ARF group comprised 56 patients (61%). Preoperative serum creatinine was higher in ARF group. During the intraoperative period, ARF group required more blood transfusions, developed more episodes of hypotension and presented longer anesthesia time. In the postoperative period, ARF group presented higher serum bilirubin and more episodes of hypotension. Dialysis was required in 10 patients (11%). The identifled risk factors for development of ARF were: preoperative serum creatinine > 1.0 mg/dL. more than five blood transfusions in the intraoperative period, hypotension during intra and postoperative periods. The identified mortality risk factors were hypotension in the postoperative period and no recovery of renal function after 30 days. CONCLUSIONS Several factors are involved in the pathogenesis of ARF after LTx and may influence patients outcome and mortality. Pretransplant renal function and hemodynamic conditions in the operative and postoperative periods were identified as risk factors for development of ARF after LTx. Nonrenal function recovery and postoperative hypotension were identified as mortality risk factors after LTx.