Acute pancreatitis (AP) after aortic surgery has rarely been reported. A retrospective review of all abdominal and thoracoabdominal aortic operations complicated with AP from January 1982 to March 1992 was performed to study the presentation and outcome of this infrequently recognized complication. Thirteen cases of AP were found among 1965 abdominal aortic operations (0.7% incidence). The distribution of the original aortic operations was as follows: eight elective abdominal aortic aneurysm repairs, two aortoiliac grafts for aortoiliac occlusive disease, and three aortorenal bypasses. Two cases of pancreatitis complicated 170 thoracoabdominal aortic operations (1.2% incidence). Ten patients had mild pancreatitis, nine were discharged without any pancreatic complications after receiving supportive treatment. Five patients with severe AP died of multisystem organ failure despite aggressive surgical treatment; 4 had infected necrosis. The overall mortality was 40 per cent; severe AP resulted in a 100 per cent mortality. The diagnosis of severe AP was usually made in the second postoperative week, significantly later (P < 0.01) than for patients with mild disease. Typically, patients with mild AP presented with hyperamylasemia at a median of 5 postoperative days, and severe AP was found at reoperation or autopsy after a period of unexplained sepsis. Five patients with mild AP were found to have biliary tract stones, with one requiring endoscopic stone extraction. In conclusion, pancreatitis is an uncommon, although perhaps underreported complication. Underreporting may be due to a lack of hyperamylasemia when severe pancreatitis is diagnosed. The severe form is diagnosed late in patients with postoperative sepsis, associated with infected necrosis, and lethal. The complication may be reduced by incidental cholecystectomy for cholelithiasis.