Unclassified mixed germ cell and sex cord stromal tumor with yolk sac and dysgerminoma component is an infrequent ovarian neoplasm. Mixed germ cell and sex cord stromal tumors are categorized into two subtypes - gonadoblastoma and unclassified mixed germ cell and sex cord stromal cell tumor (UMGSCT) . The subtype unclassified mixed germ cell and sex cord stromal tumor is rareand usually occur in females less than 10 years of age. Here we report an uncommon case of unclassified mixed germ cell and sex cord cell stromal tumor in a 22 year old female patient. CECT lower abdomen showed a multiloculated cystic left adnexal mass. Germ cell tumour marker like alpha feto protein (AFP) level was elevated. Serum testosterone and, DHEAS were also raised. Combining histomorphological and immunohistochemical findings a definitive diagnosis of unclassified mixed germ cell and sex cord stromal tumor was made. Conservative surgical removal is treatment of choice considering age of patient. During follow up after 6 months patient is found asymptomatic.