A retrospective study of 72 patients with acute biliary pancreatitis admitted to our department between 1982 and 1988 was carried out to evaluate our policy of delaying surgery in such cases. Of the 57 patients who underwent surgery, 17 were operated upon within 1 to 14 days of admission ("early operation"), and 40 patients were managed conservatively and readmitted for elective surgery about 6 weeks after resolution of the acute attack. Higher mortality and morbidity rates were observed in the "early operation" group (18% and 18% compared to 0% and 10%, respectively, P < 0.05). However, all deaths occurred in septic patients over the age of 70 who were operated on due to failure of maximal intensive medical therapy. Advanced age and early operation were found to be significant predictors of hospital mortality (P < 0.01). The two groups had similar mean hospital stay; 12 patients (30%) suffered an attack while waiting for elective surgery, however in only 3 (8%) the second attack occurred within 4 weeks of discharge from hospital. We conclude that a "delayed" operation for biliary pancreatitis is an acceptable option, and that recurrent attacks of acute pancreatitis in the time interval before the operation are avoidable if the operation is performed within 6 weeks of the initial acute attack.