In spite of diagnostic and therapeutic improvements the Surveillance Epidemiology and End Results Program data suggest that the overall cure rate for patients with ovarian cancer is 39%. Because of the dramatic difference in cure between patients with local disease (80% to 90%) and those with distant disease (15% to 25%), screening to find early ovarian cancer or its precursors is desirable. Transvaginal ultrasonography is the most efficient, accurate, and least expensive of the imaging modalities (transabdominal ultrasonography, computed tomography, magnetic resonance imaging, radioimmunoscintigraphy) for this purpose. To date, 10,000 women have been screened in three large programs; 11 cancers were detected (10 stage I, one occult stage IIIB) and all have apparently been cured. Doppler flow imaging and morphology index values improve the accuracy of transvaginal ultrasonography. A cost analysis suggests that screening costs are not yet less than treatment costs if there is to be universal screening of 27 million women at risk in the United States. However, for a population with a lifetime risk for ovarian cancer of 1%, screening will save five lives per 2000 patients screened.