The very small fraction (0.1%) of ovarian sex cord-stromal tumors are known as ovarian steroid cell tumors, not otherwise specified (OSCT-NOS). Such tumors have also classified in ovarian malign tumors. The known famous features of these rare tumors are the small size and hormone secretion. High levels of androgen secretion may cause hirsutism, hyperandrogenism symptoms and even virilization in woman. A 51-years-old postmenopozal multiparous woman was referred to our hospital with the complaint of severe virilisation and for further evaluation of high serum testosterone levels. Transvaginal sonography and MRI revealed slightly enlarged right ovary. Surgical removal of uterus and ovary was carried out. Histopathology showed a 1.5 cm occult OSCT-NOSin the stroma of the right ovary.The clinicians should keep in mind the possible diagnosis occult OSCTin case of high serum androgen levels and in the presence of severe virilization symptoms.