This work involves a retrospective analysis of serum amylase, lipase, and lipase/amylase ratio in alcoholic and nonalcoholic patients diagnosed with acute pancreatitis. The purpose of this study was to test the reliability of the Dupont ACA method with respect to the lipase/amylase ratio as a discriminator, for the etiology of pancreatitis. Thirty-six consecutive patients with the diagnosis of acute pancreatitis were studied. These patients were divided in two groups. Group I consisted of 11 patients who had presumed acute alcoholic pancreatitis. In group II, 19 patients had acute biliary pancreatitis, including two with necrcotizing pancreatitis and abscess formation secondary to cholilathiasis, five cases were idiopathic in nature, and one was thought to be medication induced (hydrochlorothiazide). In all cases, the Dupont ACA discrete clinical analyzer was used to determine serum levels of amylase and lipase. Concerning the lipase/amylase ratio, the geometric mean ratio for group I was 0.32 (range: 0.11-0.86) and for group II the mean ratio was 0.22 (range: 0.04-0.93). With P > 0.1, the difference between geometric mean ratios was not statistically significant. This study reveals that the lipase/amylase ratio would not have been a good indicator of alcoholic vs nonalcoholic acute pancreatitis. Although there was no significant statistical difference between geometric means, this study does show a significant difference in the number of individuals with serum amylase > 2000 IU/dl in nonalcoholic acute pancreatitis patients (8/25 showed levels above 2000 IU/dl) when compared to alcoholic acute pancreatitis patients (0/11 showed levels above 2000 IU/dl). Chi-square analysis between < 2000 IU/dl and > 2000 IU/dl for the nonalcoholic vs the alcoholic groups yielded a P value of 0.03.