Adnexal masses can be found in 0.19 to 8.8% of all pregnancies. Most masses are functional and asymptomatic and up to 70% resolve spontaneously in the second trimester. The main predictors of persistence are the size (>5 cm) and the imagiological morphocomplexity. Those that persist carry a low risk of malignancy (0 to 10%). Most malignant masses are diagnosed at early stages and more than 50% are borderline epithelial neoplasms. Ultrasound is the preferred method to stratify the risk of complications and malignancy, allowing medical approach planning. Pregnancy and some gestational disorders may modify the levels of tumor markers, whereby their interpretation during pregnancy should be cautious. Large masses are at increased risk of torsion, rupture, and dystocia. When surgery is indicated, laparoscopy is a safe technique and should ideally be carried out in the second trimester of pregnancy.