A case of ovarian teratoma is reported in a 11-year-old female Korean Jindo dog. Grossly, the left ovary was markedly enlarged ($5{ imes}4{ imes}4 cm in size$) and contained several cystic spaces filled with hairs and yellowish, fragile deratinous material on cross section. Histological observation of the hair and keratin containing cystic structures lined by stratified squamous epithelium, mature adipose tissue, and bone and cartilage is compatible with a diagnosis of ovarian teratoma, pyometra was also present in this dog. This is believed to be the first report on canine ovarian teratoma in Korea.