Sixty-four patients with an ultrasound diagnosis of an anomaly of the female genital tract were studied retrospectively to determine the accuracy and usefulness of sonographic examination of these anomalies in the pregnant (64%) and the nonpregnant (36%) patient. Ultrasound diagnoses in 46 patients with follow-up included: (1) bicornuate/septate uterus in 21 cases, (2) uterus didelphys in 18 cases, (3) cervical and vaginal atresia in three cases, (4) obstructed lower but normal upper genital tract in two cases, and (5) abnormal-appearing uterus in two cases. Ultrasound diagnosis was compared with hysterosalpingographic and/or surgical findings in 43 patients and with physical examination in three patients. Scan results were classified as diagnostic in 26%, confirmatory in 63%, and incorrect in 11%. Ultrasound is a reliable clinically useful method of studying genital tract anomalies in gynecologic patients.