All year old boy with craniopharyngioma associated with hypogonadotropic hypogonadism, obesity and severe fatty metamorphosis of the lilver is described with review of literatures. The liver biopsy revaled severe fatty metamorphosis with periportal infiltration. It is highly suggested that morbid obesity, a manifestation of the craniopharyngioma, may be the etiology of the fatty metamorphosis of the liver.