The review deals with neuroblastoma, its frequency, localization, features of its clinical course and microscopic patterns. The ability of neuroblastoma for maturation and sometimes for spontaneous regression as well as the relationship between tumors of the autonomous nervous system and the so-called neuroblastoma in situ and von Recklinghausen's disease are discussed. Some light and electron microscope differential diagnostic criteria are given. An attempt is made to explain certain clinico-biological features of neuroblastoma from the point of view of current embryological data.