In the right eye of a 2½-year-old boy a markedly prominent tumor, arising from the posterior pole, was found. The clinical diagnosis was retinoblastoma and the eye was removed. Histologically, however, this appeared to be a medulloepithelioma originating in the optic disc and in the posterior retina: an extremely rare localization as these tumors usually originate in the ciliary region. The tumor mainly consisted of neuroectodermal elements in several degrees of differentation giving the aspect of a benign (hamartomatous) embryonal brain tumor rather than those of a retinal tumor. Some aspects of the nomenclature are discussed.