Background: Carcinoid tumors are rare neoplasms of the diffuse peripheral neuroendocrine system which produce biological amines and various peptides. Carcinoid tumors most commonly occur in the gastrointestinal tract. Primary ovarian carcinoids are rarely seen; they consist less than 0.1% of all ovarian cancers and 0.3% of all carcinoid tumors.Case: Here, we present a rare case of primary carcinoid tumor, insular type, arising in a mature cystic teratoma of the ovary. Conclusion:Surgical excision of the tumor is usually sufficient treatment for most of the patients.