Mature cystic teratoma is the most frequent benign ovarian neoplastic lesion in adolescents and is generally composed of fully differentiated tissue arising from multipotential three germinal layers. It accounts for approximately 50% of benign ovarian tumors in childhood. Rarely, a bilateral, synchronous, or metachronous presentation can be observed, supporting a conservative approach as the first surgical approach. We report a case of an ovarian mature cystic incarcerated in indirect inguinal hernia in a 15-year-old girl undergoing ovary-sparing surgery. To our knowledge this is the first case of such lesion incarcerated in an inguinal hernia reported in literature.