Patients with acute pancreatitis may present with mild or severe disease, the latter comprising a minority of cases but accounting for most of the morbidity and mortality associated with this disease. Contrast-enhanced computed tomography is the mainstay of imaging patients with acute pancreatitis and is widely used in both the community and academic settings. A variety of retroperitoneal morphologic changes are readily depicted, and the correct assessment of these abnormalities is imperative for management. The purpose of this review is to describe the imaging evaluation of patients with acute pancreatitis by using the 1992 Atlanta Symposium classification and definitions to describe local complications depicted on contrast-enhanced computed tomography. Correlation with the proposed revision of Atlanta Symposium definitions set forth by the Acute Pancreatitis Working Group will be discussed. © 2008 AGA Institute.