Objective: Primary spindle cell ovarian sarcomas are rare lesions of the genital tract. The authors report the case of a patient with a spindle cell ovarian sarcoma. Materials and Methods: A 48-year-old woman presented with a left adnexal mass. Pretreatment evaluation suggested no evidence of metastatic disease until ultrasound revealed a sizable solid cystic lesion in the left adnexal region. Results: The patient first underwent laparoscopic left salpingo-oophorectomy. Pathological examination and immunohistochemistry demonstrated a spindle cell ovarian sarcoma. Follow-up surgery was laparoscopic hysterectomy + right salpingo-oophorectomy + ometectomy; pathology was normal. Conclusions: Women undergoing gynecologic care would benefit from routine evaluation of the ovaries to detect these rare neoplasms.