OBJECTIVE To develop a new noninvasive scoring system using clinical signs and symptoms, CA-125 levels, sonographic findings, and transvaginal color and pulsed Doppler parameters for preoperative recognition of ovarian endometriosis. METHODS A 5-year prospective study in patients undergoing laparotomy and laparoscopy. METHODS Department of Obstetrics and Gynecology, University of Zagreb, Sveti Duh Hospital, Zagreb, Croatia. METHODS Six hundred fifty-six benign and malignant adnexal masses, among which 103 were surgically proved to be ovarian endometriosis. METHODS All patients undergoing laparotomy and laparoscopy were examined by transvaginal ultrasonography with color Doppler imaging. Serum levels of CA-125 were measured the day before surgery. METHODS The total score was applied in all patients with adnexal masses. RESULTS The scoring system proved to be very useful in distinguishing ovarian endometriosis from other benign and malignant ovarian lesions, with a sensitivity of 99.02% and a specificity of 99.64%, compared with morphological scoring system's sensitivity of 83.91% and specificity of 97.12%. CONCLUSIONS The new noninvasive scoring system improves significantly the ability to discriminate between endometriosis and other benign and malignant ovarian entities.