Steroid cell tumors (SCT), not otherwise specified (NOS) are particularly rare ovarian sex cord-stromal tumors, which comprise <0.1% of all ovarian tumors. These tumors are uncommon in patients' prior to puberty without any typical syndromes involving hirsutism, virilization and hypertension. We here in present the case of a 5-year-old female patient who presented with sudden abdominal pain, repeated vomiting and a pelvic mass. Our patient underwent urgent exploratory laparotomy and right salpingo-oophorectomy and the histopathological examination revealed an ovarian SCT-NOS. The patient has been followed up for 5 years since the surgery, without evidence of disease recurrence. The purpose of this study was to discuss the available information on the presentation, diagnosis and recommended treatment of ovarian SCT-NOS; and describes the immunohistochemical characteristics of these tumors.