From the published studies it would appear that ultrasound is a very sensitive tool for identifying advanced stage ovarian cancer. The identification of Stage I ovarian cancer with ultrasound screening is more problematic since only 25 to 50% of ovarian cancers are identified in low-risk and high-risk respectively using this technique. Due to the low annual prevalence of ovarian cancer routine screening of premenopausal women or low-risk women after the menopause is unlikely to be cost-effective. The subject of biologic markers to screen for ovarian cancer is addressed elsewhere in this book. It is clear that a primary screening test less expensive than ultrasound is needed. The multicenter National Cancer Institute screening program is designed to evaluate possible new markers. At this time ovarian cancer screening should be done in high-risk groups under careful investigational scrutiny. Patients who are high-risk should be carefully advised of the limitations of diagnostic ultrasound in identifying early stage disease. Transvaginal ultrasound in expert hands is sensitive but not ideally specific for discriminating benign from malignant disease. The judicious use of color Doppler evaluation may help discriminate with greater specificity.