Surgical abnormalities of the adnexa in children and adolescents include a variety of ovarian and paraovarian lesions ranging from benign functional cysts to malignant tumors, torsion of the ovary and/or the fallopian tube, and adnexal infectious lesions ranging from salpingitis to tubo-ovarian abscesses. Presentations vary from asymptomatic pelvic masses to acute abdomen, while some ovarian tumors might present with precocious puberty or virilization. Acute pain might be caused by hemorrhage or rupture of ovarian or paraovarian cysts, adnexal torsion or adnexal infection. Differential diagnosis of adnexal masses should include periappendiceal abscess in all age groups, and endometriomas and ectopic pregnancy in adolescents. This review provides guidance on the differentiation between adnexal abnormalities, based on important clues from clinical assessment and diagnostic work-up, and ultimately on the decision making about the need for surgery, its level of urgency and the type of surgery to clinicians of all specialties involved in the care of young females.