© 2016 by Erciyes University School of Medicine.Sex cord-stromal tumors with annular tubules (SCTAT) of the ovary are rare. They have two clinical presentation forms: the syndromic form, which is associated with Peutz-Jeghers syndrome, and the non-syndromic form, which is frequently seen in the second or third decades. We describe a 13-year-old patient who underwent left oophorectomy. Macroscopically, the mass was 16×13×8 cm in diameter, encapsulated, and lobulated. It showed a yellow-to-orange solid cut surface with small cystic areas and hemorrhagic cleft-like spaces. Microscopically, the tumor had nodular areas that were separated with fibrous stroma. They were composed of tubules, which were lined by columnar shaped cells with eosinophilic cytoplasm, nuclear palisading, and central Periodic Acid Schiff (PAS)-positive eosinophilic hyaline bodies. Immunohistochemically, the tumor cells were strongly positive for inhibin. Finally, the tumor was diagnosed as non-syndromic ovarian SCTAT.