Objective To estimate the performance of currently available tests in detecting ovarian cancer in asymptomatic women.Methods Systematic review of prospective screening studies.Results Twenty-five studies were identified: sixteen studied women at average risk and nine studied women at higher risk. Most studies evaluated only one screening method, were small, detecting few cancers, and gave few follow up details. Sensitivity estimates are therefore imprecise. In a typical larger study, reported sensitivity of ultrasound screening at one year was around 100% (95% CI 54%–100%), while the sensitivity of CA125 measurement followed by ultrasound (multimodal screening) was about 80% (95% CI 49%–95%). False positive rates ranged between 1.2% and 2.5% for grey scale ultrasound, between 0.3% and 0.7% for ultrasound with colour Doppler and between 0.1% and 0.6% for multimodal screening. This implies that, in annual screening of a population with an incidence of 40 per 100,000, and if no cancers were missed, between 2.5 and 60 women would undergo surgery for every primary ovarian cancer detected.Conclusions Ultrasound and multimodal screening can detect ovarian cancer in asymptomatic women, but there is currently no evidence on whether screening improves outcome for women in any risk group. On-going randomised controlled trials should establish the magnitude of any benefit of screening. The low prevalence of ovarian cancer in the population, and its rate of progression, may limit the potential cost-effectiveness of screening.