The aim of this study was to investigate the clinicopathologic features, treatment and outcome of seven patients with an ovarian Sertoli-Leydig cell tumor (SLCT). Five patients presented with feminization, two with accompanying virilization. One presented with amenorrhea alone. Three of the five patients showing feminization symptoms had endocrine-related diseases. Histologically, five tumors were well differentiated, the other two were poorly differentiated. The latter two patients were misdiagnosed as having an ovarian epithelial carcinoma or granulosa cell tumor from frozen sections. Immunohistochemistry showed that the tumors were calretinin-positive in two patients and one was inhibin-positive. Four patients underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy(TAH/BSO) and two were treated by unilateral salpingo-oophorectomy. Among them, two patients received adjuvant chemotherapy. Six patients were free of disease in a follow-up of 2-34 years and one achieved a pregnancy. The remaining patient recurred 4 years later. Feminization as well as virilization might provide important clues for a preoperative diagnosis. Histological misdiagnosis is probable in poorly differentiated tumors. Conservative surgery including retention of fertility can be considered. However, the tendency for recurrence in poorly differentiated tumors should be considered.