An increase in the incidence of adnexal masses uncovered during pregnancy has occurred concurrently with the adoption of near universal use of prenatal ultrasound. The majority of these masses resolve by the second trimester. Persistent masses continue to be at risk for significant sequelae such as torsion, rupture, and obstruction of labor. These events may result in the need for emergent surgical intervention with increased risk of adverse outcome for both mother and fetus. In addition a small risk of cancer exists and extended delay in diagnosis should be avoided. As such, surgical excision of persistent adnexal masses should be entertained at approximately 16 to 20 weeks of gestation. In the approximately 5% of cases in which an adnexal masses proves to be a malignancy, appropriate staging may be safely performed. In selected cases, chemotherapy should at least be entertained.