Acute acalculous cholecystitis developed in six patients recovering from repair of an abdominal aortic aneurysm. All patients were men with significant concurrent medical illnesses, and three patients had undergone operation for a ruptured aneurysm. Symptoms appeared at a mean of 3 weeks postoperatively and consisted of right upper quadrant pain, fever, leukocytosis, and slight elevation of liver function test results. Treatment consisted of cholecystostomy (three patients) or cholecystectomy (three patients), with an overall mortality rate of 50%. When cholecystitis is suspected after aortic aneurysm repair, early confirmation of the diagnosis should be obtained with ultrasound or a technetium hepatobiliary scan and cholecystostomy or cholecystectomy undertaken if the patient does not rapidly improve with medical management.