The diagnosis of malignant melanoma metastatic to the ovary is rare. The primary lesion can be followed by metastasis site after few years. We describe the case of a 31 year-old woman who presented an acute pelvic pain in relation with a right ovarian cyst. This patient presented many metastatic melanoma few years ago. The ovarian metastatic diagnosis is strongly suspected by the use of preoperative magnetic resonance imaging. The operating piece immunohistochemical studies demonstrated the positivity for S-100 protein, HMB-45 and negativity for keratin in cytoplasm cells. The surgical treatment (right salpingo-oophorectomy) would be followed by chemotherapy. The patient had a good postoperative recovery. She is in good health at six months.