A rupture of a hypogastric aneurysm presenting as a sciatic nerve compression is reported. The diagnosis was delayed as the lumbar spine CT Scan was normal. The aneurysm was visualized with a CT Scan of the pelvis, it was located in the front of the sacrum and continued through the greater sciatic foramen. After aneurysmorrhaphy the pain disappeared but the paralysis wasn't improved. 28 cases of ruptured hypogastric aneurysm have been collected by reviewing the literature, eight of them have simulated nerve compression.