Seventy women (age 32-47 yrs) with a history of menorrhagia were evaluated by transvaginal sonography, hysteroscopy, and endometrial biopsy. Hysteroscopy revealed a normal uterine cavity in 60 patients, endometrial polyps in 4, and submucous myomas in 6. Endometrial biopsy revealed normal histology in 67 women and 3 cases of cystic endometrial hyperplasia. All patients underwent endometrial resection using the 27F resectoscope followed by coagulation with the rollerball. Glycine 1.5% was used as the distention medium. Endometrial resection was carried out under paracervical block plus intravenous propofol. Oral medroxyprogesterone acetate (MPA) 20 mg/day for 2 months was prescribed postoperatively for 40 women. The remaining women received a placebo. All patients were evaluated by transvaginal sonography at 1, 3, and 6 months after resection. The frequency of amenorrhea was 40% in the placebo group and 70% in the MPA group. These initial results suggest that postoperative treatment with MPA increases the frequency of amenorrhea after endometrial resection.