We have endeavored to define the incidence of pancreaticoduodenal artery aneurysm associated with stenosis of the celiac axis and to address modalities in this setting. This association was found in 23 of 34 cases. Aneurysmal dilation of the pancreatic arteries associated with celiac axis stenosis is not accidental and seems to be due to increased flow through the peripancreatic arteries. Hemorrhagic complications, i.e., peripancreatic hematoma, hemoperitoneum, ductal hemorrhage, were the initial manifestation in 16 of 34 cases. Isolated aneurysms were treated by resection, exclusion or embolization without any complications. For associated aneurysms, resection and exclusion were employed. Pancreatoduodenectomy was required in three cases in which bleeding was uncontrollable. In six cases, the celiac axis was restored either by arterial reconstruction, aortohepatic bypass, or division of the arcuate ligament. Four patients died. All had been operated on for ruptured aneurysm. None of the deaths was directly due to ischemic compromise of the celiac artery bed. Because of the risk of rupture, all pancreaticoduodenal artery aneurysms should be treated surgically after appropriate investigation to detect associated celiac axis stenosis. Revascularization of the celiac axis is indicated whenever blood flow is reduced or, routinely, to reduce high peripancreatic collateral flow, particularly when collaterality is due to arcuate ligament-related stenosis.