In this paper, we present an extremely rare case of a primary intrapulmonary neurogenic tumor, in which localization of S-100 protein was investigated using immunohistochemical staining. The patient, who was a 47 year old man, experienced no symptoms, however, a routine chest X-ray revealed a round tumor like shadow in the hilar area of left lung. To confirm and cure the mass, surgery was performed. Histopathological examination of the excised tumor revealed it to be a primary intrapulmonary neurilemmoma. Immunohistochemical staining demonstrated the presen e of S-100 protein in the tumor cells.