Using immunohistochemical procedures numerous nerve fibers have been found in all cell layers of human epidermis. These nerves originate from nerve trunks in the dermis, enter the epidermis, then divide distally to eventually end in small enlargements, near the surface of the skin and in deeper areas. Some endings may be external to stratum granulosum cells. Epidermal nerves appear to have a three-dimensional territorial distribution in relationship to the skin's surface. The presence of epidermal nerve fibers was confirmed by electron microscope studies. The nerves are presumed to be sensory in nature. The existence of epidermal nerve fibers will necessitate changes in present theory of structure and function of peripheral sensation.