Of 340 patients with various manifestations of herpetic disease, 261 showed predominant involvement of the peripheral nervous system. Apart from ganglioneuritis of the cranial and spinal nerves there occurred forms accompanied by inflammatory changes in the liquor, commissural processes in the meninges, involvement of the anterior roots and vegetative ganglions. The results of clinicovirological comparisons and differentiation of herpetic diseases as well as their initial manifestations are reported. Some aspects of the pathogenesis of herpetic diseases are discussed.