Injury of the lumbar arteries is a cause of potentially life-threatening retroperitoneal hemorrhage. Twelve patients who sustained massive hemorrhage of the lumbar arteries associated with lumbar spinal fractures and/or pelvic fractures are described. Computed tomography (CT) was helpful by revealing a distinct separation of the lumbar hemorrhage from the hematomas associated with pelvic fracture. On arteriograms, stasis within lumbar extravasation was manifested as globular or streaky accumulations of contrast medium, pseudoaneurysms or diffuse "staining," or opacification of a fracture site. Multiple lumbar bleeding sites were seen frequently. Embolization with pledgets of absorbable gelatin sterile sponge controlled bleeding in ten patients. Abdominal aortography should be an essential part of the arteriographic evaluation of retroperitoneal hematomas associated with pelvic fractures, especially when there are lumbar fractures. Selective lumbar arteriography should be performed for confirmation when there is suspicion of lumbar artery injury on the basis of aortographic findings. Embolization with pledgets of surgical gelatin is effective in controlling hemorrhage from these injuries.