Thirty-four patients, with a history of persistent abnormal uterine bleeding and dilatation and curettage or suction curettage performed within the previous year, were evaluated by office hysteroscopy and biopsy. For 16 patients (47%) the hysteroscopic diagnosis was in agreement with the curettage. Hysteroscopy revealed more information in 18 patients (53%): 8 had polyps, 6 had submucous or pedunculated myoma, 2 had endometrial neoplasia, 1 had myoma and polyp, 2 had endometrial neoplasia and 1 had synechia. Moreover in 3 patients with diagnosis of suspected myoma by curettage, hysteroscopy revealed a normal cavity. The high incidence of missed diagnosis of pathologic conditions by "blind" curettage supports the opinion that diagnostic hysteroscopy is the method of choice in the evaluation of abnormal uterine bleeding.