Mature cystic teratomas constitute 10–20% of all ovarian neoplasms. Malignant transformation is very rare occur- ring in only 0.1–2% of mature teratoma cases. Malignant melanoma is among the least common transformations. Herein, we describe a case of young woman initially undergoing evaluation for infertility who was found to have malignant melanoma arising in a mature dermoid cyst. She subsequently underwent unilateral salpingo- oophorectomy with staging procedure with benign pathology. There was no need for adjuvant therapy and the patient is without disease to date (nearly 10-months in follow-up now). We reviewed the existing literature and this is one of only a few cases documented in the last decade.