The majority of women with ovarian cancer present with advanced-stage disease. Women with early-stage ovarian cancer have a much better chance of achieving a cure than do women with late-stage disease. This difference makes screening for ovarian cancer, with the hope of detecting it in its presymptomatic state, an attractive concept. Unfortunately, efforts to demonstrate that screening for ovarian cancer in the general population can decrease mortality have been disappointing. Current screening techniques do not have high enough sensitivity and specificity to be applied to the general population, because the low prevalence of the disease in the general population leads to very low positive predictive values for the available screening tests. However, applying current screening strategies to certain high-risk populations (women who carry mutations in the BRCA1 or BRCA2 genes, or with strong family histories of breast/ovarian cancer) is a reasonable approach and may result in acceptably high positive predictive values. This article discusses the results of screening studies using serum CA-125, sonography, other serum markers, and combinations of these tests. Screening for women of average risk is not recommended, although such women should be encouraged to participate in clinical trials whose end points are either the demonstration of the impact of screening on mortality, or the development of novel screening strategies. Screening with twice yearly transvaginal sonography and serum CA-125 testing is recommended for women at high risk for ovarian cancer, although prospective data are needed regarding the impact of such screening on stage of cancer detected, quality of life, and psychological distress, as well as the costs--both personal and societal--of screening.