Malignant melanoma is a neoplasm of the skin and mucous membrane which very rarely occurs in the ovary. Malignant melanomas occurring in the ovary must be differentiated from primary and metastatic malignant melanoma. Primary malignant melanoma of the ovary is extremely rare and is thought to originate from a cystic teratoma. Malignant melanoma of ovary without evidence of residual teratoma must be considered metastatic even in the absence of a previously cutaneous or mucocutaneous lesion. Opinions about its histogenesis, diagnostic criteria and elective treatment are controversial because of rare manifestations, and the prognosis remains poor in spite of the variety of therapeutic measures. After thoroughly surveying the specific literature, we report case of malignant melanoma with multiple metastases located in the stomach, the omentum and both ovaries with unknown site of primary origin.