BACKGROUND: Endometriosis is rare in postmenopausal women. We report a case of invasive pelvic endometriosis in a postmenopausal woman requiring a supralevator pelvic exenteration for palliation of symptoms and for tissue diagnosis. CASE: A 65-year-old woman with a history of total abdominal hysterectomy and bilateral salpingo-oophorectomy for endometriosis at age 43 years presented with acute vaginal bleeding, hematuria, and a recently diagnosed pelvic mass. Biopsies revealed endometriosis, and she underwent supralevator pelvic exenteration with vaginectomy, end colostomy, ileal conduit, and coagulation of endometriotic implants. Pathologic examination showed invasive endometriosis and no evidence of malignancy. CONCLUSION: Endometriosis should remain on the differential diagnosis for pelvic mass in a postmenopausal woman, although suspicion for malignancy should remain high.