With the advent of high-frequency transvaginal ultrasonography, new opportunities are presented to better define ovarian lesions. The goal of this study was to develop a scoring system using transvaginal sonographic characterization of pelvic/ovarian lesions. Our purpose was to maximize the discrimination between benign and malignant entities. Transvaginal sonographic pelvic images of 143 patients were correlated with surgical findings or histopathology. Of 281 ovaries, 108 had benign lesions (30 endometriomas, 24 teratomas, 21 simple cysts, and 33 other abnormalities) and 20 had malignancies. The scoring system devised was useful in distinguishing benign from malignant masses, with a specificity of 83%, sensitivity of 100%, and positive and negative predictive values of 37 and 100%, respectively. Further experience and refinements of this method of scoring should maximize the benefit of high-resolution transvaginal sonography of ovarian lesions.