The presentation of adnexal masses in childhood differs from that in adult women. Children may present with poorly localized symptoms or precocious puberty. Ovarian cysts occur throughout development; ovarian tumors are less frequent but occur in all age groups. Congenital malformations may present with signs or symptoms of an adnexal mass. Occasionally adnexal findings may suggest the presence of an underlying syndrome. Assessment of the patient's developmental, hormonal, and pubertal status is necessary to ensure an accurate diagnosis. Treatment options must consider risks to ovarian function and future fertility.