Sciatic endometriosis may cause cyclic sciatic pain and a sensorimotor mononeuropathy. Neurophysiologic tests and conventional radiologic examinations are of little value in delineating this lesion, but the pelvic CT appearance of sciatic endometriosis is distinctive. Suppression of the ovarian cycle and surgical removal of endometriosis and adhesions from in and around the sciatic nerve usually relieve the pain and stabilize neurologic function.