Ovarian leiomyoma is a rare form of the ovarian mesenchymal neoplasm and about 50 cases have been reported in the literature. It is believed that many cases may go unnoticed because they are usually small in size and frequently mistaken for the more common fibroma or fibrothecoma. Its origin is still controversial and many possibilities are considered including the smooth muscle in the blood vessel wall of the hilum or the multipotential ovarian stromal cell. Herein we describe two cases of ovarian leiomyoma with its characteristic histologic finding.