Ovarian cancer is among the most dreaded cancers since it is often found at a late stage where the opportunity for extended survival is poor. Ultrasound has been utilized in several ovarian cancer screening trials in asymptomatic women in order to detect ovarian cancer at early stages where survival rates are high. Efforts to improve screening for ovarian cancer are ongoing. While ovarian cancer screening in asymptomatic women is not recommended for clinical application currently, the care of women with adnexal masses found by ultrasound in clinical practice can benefit from close evaluation of the evidence obtained from large prospective ovarian cancer screening trials and by relating this evidence to recent advances in the understanding of different types of ovarian cancer. Post-menopausal women who have an adnexal mass discovered by ultrasound have a much higher risk of developing ovarian cancer than women with normal ultrasound. The preponderance of reported evidence indicates that ultrasound monitoring of an adnexal mass is safe, cost effective and can achieve an improved positive predictive value in detecting ovarian cancer when ovarian abnormalities resolve during surveillance. Proposals to arbitrarily discontinue ultrasound monitoring can negatively impact patient care and generate medical-legal actions, especially because there is no evidence to support safe discontinuation. In this review, we outline a rationale for continuing ultrasound surveillance of ovarian abnormalities.