With respect to the histogenesis of the neurofibroma, there are many controversies, since von Recklinghausen postulated that neurofibromas are mainly fibrous tumors arising from the connective tissue of the nerve sheaths. According to the recent studies through the electron microscope, the neoplastic perineurial cells are regarded as the main components of the tumor. So, the neurofibroma enucleated from the median nerve at the level of proximal arm without resulting neurologic sequale was examined through the light- and electron microscope. Ultrastructurally, this tumor is composed of the perineurial cells, fibroblasts, and collagen fibers. The predominant perineurial cells show distinct basal lamina, and contain abundant microfilaments.