Traumatic retroperitoneal hematoma (RPH) may arise from injury to bony structures, major blood vessels, and intestinal or retroperitoneal viscera. To categorize the management of RPH, the retroperitoneum may be divided into three zones. Zone 1 (central) extends from the esophageal hiatus to the sacral promontory. Zone 2 (lateral) extends from the lateral diaphragm to the iliac crest. Zone 3 (pelvic) is confined to the retroperitoneal space of the pelvic bowl. For the traumatized patient with RPH, laparotomy is mandated by persistent hemodynamic instability despite intensive volume replacement. The judgment of whether and when to explore the retroperitoneal hematoma is guided by the mechanism of injury (blunt or penetrating) and the location of the RPH. RPH localized to the upper central area (Zone 1) after penetrating trauma implies injury to the great vessels and always requires urgent surgical exploration. RPH in other zones should be evaluated by CT and/or angiography; ongoing hemorrhage may respond to therapeutic embolization.