The widespread use of vaginal ultrasound as an integral part of the gynecologic clinical examination in many countries has led to the unexpected finding of adnexal mass. The implications of the finding of an adnexal mass in an asymptomatic postmenopausal woman can be serious if it is malignant and is not excised, because ovarian cancer has an indolent course and when it becomes symptomatic it is often fatal. The aim of the present review is to discuss the evaluation and management of incidental adnexal masses in postmenopausal women. Despite careful evaluation with ultrasound and biomarkers, a small number of patients will remain without a conclusive diagnosis. It is our opinion, based on empirical evidence discussed here, that conservative therapy with observation can be safely applied in the majority of these patients.