The purpose of this study was to ascertain the influence of acute pancreatitis upon the course of chronic pancreatitis, its complications, the need for surgical treatment, and mortality, in alcoholic men. The studied population was composed of 222 men; 110 had never had acute pancreatitis and 112 had presented at least once with acute pancreatitis. The cumulative probability to have a first bout of acute pancreatitis was 41.5 percent, 2 years after the onset of chronic pancreatitis. There was no difference in follow-up but clinical onset of chronic pancreatitis was earlier in the "acute pancreatitis" group. There was no difference in the prevalence of biliary strictures, non-alcoholic hepatic disease or need for surgery. On the contrary, diabetes mellitus, alcoholic hepatic disease were less frequent and pseudocysts were more frequent in the "acute pancreatitis" group. We observed 56 deaths. The comparison of mortality and cumulative survival rates showed a lower mortality in the "acute pancreatitis" group (p less than 0.02 and 0.05, respectively). The main causes of death were alcohol-related hepatic disease, postoperative mortality, and carcinoma Alcoholic cirrhosis was more frequent in patients who died in the "no acute pancreatitis" group. We conclude that: a) acute pancreatitis is an early complication of chronic pancreatitis in one case out of two; b) clinical onset of chronic pancreatitis occurs earlier in patients who presented with acute pancreatitis; c) need for surgery is not different; d) alcoholic hepatic disease is more frequent in the "no acute pancreatitis" group; e) mortality is lower in the "acute pancreatitis" group.(ABSTRACT TRUNCATED AT 250 WORDS)