A 2-month-old female mixed cat was emaciated due to dysphagia, and inspection of the mouth revealed a 2 cm pedunculated mass elongated from the palate, which occupied the oral cavity. The mass was surgically removed, and histopathological examination revealed that the tumor was composed of three germ cell layers: ectodermal (skin and skin appendages), mesodermal (cartilaginous and osseous structures), and endodermal (glandular and respiratory mucosa) tissues. An immature teratoma was diagnosed because of the presence of immature neuroectodermal tissues, and the presence of nephroblastic components was a characteristic finding in this case. This is the first report of an oropharyngeal teratoma in cats and the first case of an immature teratoma with nephroblastic components in a domestic species.