Neurologic deficits uncommonly occur following successful aortic surgery for aneurysm. Two cases are presented in which peripheral neuropathy precipitated the diagnosis of ruptured aneurysm. Both patients had large retroperitoneal hematomas at operation, and the neuropathy was due presumably to compression of the femoral and obturator nerves. Neither patient has shown significant improvement in function in the affected muscles after operation. This represents an important diagnostic sign with leaking or ruptured abdominal aortic aneurysm.