Endometriosis of the sciatic nerve is rare but must be included in the differential diagnosis of sciatic pain. Patients present with typical signs and symptoms of sciatica, which are cyclic in nature. Electromyography and computed tomographic scanning are useful in diagnosis. At laparoscopy or laparotomy, a characteristic "pocket sign" is frequently seen, and may be the only clue to the presence of endometriosis. The patient often requires definitive surgery with total abdominal hysterectomy and bilateral salpingo-oophorectomy. However, conservative surgery with excision of the endometriosis from the nerve can be successful in selected patients who wish to preserve reproductive function.