Tumors analogous to the so-called Wilms9 tumor of children have been observed in many domesticated species of animals. These growths, which I prefer to designate embryonal nephroma, have been reported in swine (2, 4), rabbits (1, 5, 8, 9, 10), chickens (6, 7), and in one instance in a cow (4). So far as I know, this variety of tumor has not been reported as occurring in sheep, which species seems more or less resistant to neoplasia in general (3). Recently I have had the opportunity to examine an embryonal tumor of the kidney of a sheep, found by Dr. R. B. Leeper, Federal inspector, in a Denver, Colorado, packing establishment. History of Case A female sheep, aged approximately eight months, weighing 45 pounds, was considered to be normal when examined ante mortem and was slaughtered with others with the expectation of using the carcass for food. At necropsy the physical condition of the animal was considered “fair”; the only gross abnormality observed was a huge mass affecting one kidney and a few discrete, nodular masses of tissue in the lung. The sublumbar lymph nodes were considered to be enlarged.