A total of 267 consecutive patients presenting with acute pancreatitis were studied retrospectively. We analysed the collected data to determine the prevalence of acute renal failure (ARF), and factors significantly predisposing to its occurrence and outcome. The prevalence of ARF in our patients was 16%. Only 2% had isolated ARF. Seventy-three percent of patients with additional organ system failure suffered ARF after the onset of other organ failure. The number of organ system failure was significantly greater before, compared to after, the development of ARF. Using multiple logistic regression we found that pre-existing chronic disease and cardiovascular and haematological failure were independent risk factors positively related to the development of ARF, whereas systemic infection was not. Overall mortality from ARF was 81%. Chronic disease, local complications and the presence of additional organ system failure and their number significantly increased mortality in ARF patients. No patients requiring renal replacement therapy survived. ARF is a common complication of severe acute pancreatitis, but occurs late in the disease course, and mostly preceded by other organ system failure. The prognosis of patients with ARF is extremely poor, indicating that more emphasis should be placed on prevention of ARF.