A 35-month-old female exhibiting precocious puberty of cerebral origin was found to have a suprasellar mass. The provisional diagnosis was hypothalamic hamartoma, and the mass was totally removed through a right frontotemporal pterional craniotomy. The mass, which was situated in the suprasellar and prechiasmal region, was isolated, adhering to and compressing the pituitary stalk and diaphragma sellae. Histological examination showed it to contain normal pituitary gland cells without evidence of neoplastic differentiation. The final diagnosis was precocious puberty due to a suprasellar ectopic pituitary gland. This is believed to be the first such case reported.