Primary malignant melanoma arising in an ovarian cystic teratoma is exceedingly rare event with an estimated incidence of 0.2-0.8%. So far, there have been approximately only 47 relevant reports. We report a case of primary malignant melanoma of the ovary arising in a cystic teratoma here. Moreover, we review systematically the disease from the following aspects, that origin, clinical characteristics, accessory examination, pathological features, diagnosis, differential diagnosis, treatment, prognosis.