The ruptured abdominal aortic aneurysm is a rare, but life-threatening disease that demands fast diagnosis. We report in the following about a patient who was admitted with symptoms of urinary obstruction and an acute abdomen. Ultrasound investigation at admission confirmed urinary obstruction of the right kidney. Causative for that however was a right pararenal ruptured abdominal aortic aneurysm, which led secondarily to ureter compression. Thus, in our opinion, primary ultrasound examination represents an important instrument in differential diagnosis.