Adnexal masses are uncommon in the pediatric and adolescent population. The differential diagnosis includes ovarian lesions, tubal or paratubal lesions, nongynecologic lesions, and lesions related to infection or pregnancy. Presenting symptoms vary and may include acute abdominal pain, mass effect, and less commonly, precocious puberty and vaginal bleeding. Most of these lesions represent benign pathology, but malignant lesions are identified in a small subset of patients, and appropriate surgical and postoperative management is essential. It is important for clinicians caring for these patients to understand the differential diagnosis of an adnexal mass, to facilitate correct management (whether surgical or nonsurgical) and necessary referrals where appropriate. This review explores the etiologies, presenting symptoms, and appropriate management options for pediatric and adolescent patients with adnexal masses. There are few clinical trials guiding the management of these patients, and existing data comprise primarily case series and retrospective studies.