The purpose of the study was to evaluate the efficacy of norethindrone acetate (NA) treatment in 52 women with dysmenorrhea, dyspareunia, noncyclic pelvic pain who had a diagnosis of endometriosis by laparoscopy.Dysmenorrhea and noncyclic pelvic pain were relieved in 48/52 (92.3%) and 25/28 (89.2%) of patients, respectively. Overall pain relief was obtained in 49/52 (94.2%) of patients. Breakthrough bleeding, of variable severity, was the most common side effect experienced by 30 patients (57.6%); however, only 4 patients (7.7%) dropped out for this side effect. One other patient dropped out for severe breast tenderness, and three for noncyclic pelvic pain. In general, treatment was successful in 44/52 (84.5%) of patients with the above symptoms.NA seems to be a cost-effective alternative with relatively mild side effects in the treatment of symptomatic endometriosis.