Abdominal aneurysms and pseudoaneurysms represent an important finding every emergency radiologist must detect. True aneurysms are usually incidental to the presenting complaint, whereas pseudoaneurysms are nearly always symptomatic. We review the demographics, pathophysiology, clinical presentation, computed tomographic appearance, treatment approaches, and prognosis of visceral aneurysms and pseudoaneurysms involving splenic, gastroduodenal, hepatic, superior mesenteric, and renal arteries.