Leiomyoma is a Benign Mesenchymal Tumor frequently seen in uterus but is    rare in ovary. Primary Ovarian Leiomyoma accounts for 0.5 to 1.0% of all        benign ovarian tumors¹; seen in women aged 20 to 65 years old.² It is usually  diagnosed incidentally during Pelvic examination or histopathological examination after Surgery. Here we report a case of large Ovarian Leiomyoma in 40 years    old woman.