Germ cell tumors may be classified as germinomas, which represent approximately two thirds of all intracranial germ cell tumors, and non germinomas, which include embryonal carcinomas, choriocarcinomas and teratomas. Teratoma may be mature(benign) or immature (malignant). Mature teratomas located in the anterior fossa are extremely rare and have benign characters. Nongerminomatous germ cell tumors, especially teratomas and choriocarcinomas, tend to occur in younger children. Mature teratoma in adults is very rare. In this paper we report a twenty-eight years old patient with mature teratoma in anterior fossa and pneumocephaly.