"Pseudoaneurysm" is a term that describes disruption of an artery with patent flow in a defined space beyond the confines of the vessels. A pseudoaneurysm can involve any vascular bed and is usually associated with direct arterial injury or erosion of an artery by an adjacent tumor or inflammation. In this article, we discuss different clinical settings and various imaging modalities such as ultrasound, computerized tomography, magnetic resonance imaging, as well as conventional angiography used for the diagnosis of pseudoaneurysms. We also describe the role of newer endovascular, percutaneous, and traditional surgical approaches for the treatment of visceral and peripheral pseudoaneurysms in different clinical circumstances. © 2009 Mosby, Inc. All rights reserved.