In studying autoimmune diseases of the human peripheral nervous system (PNS), in vitro studies involving the use of cultured rat Schwann cells, neurons, and disease-inducing immune system cells have provided basic information about disease pathogenesis. For example, T-cells that induce experimental allergic neuritis have been shown in vitro to damage Schwann cells, the target cell in these diseases. However, before making contact with Schwann cells, these T-cells must first pass through the blood-nerve barrier. Despite the importance of this interaction, no studies employing PNS endothelial cells in coculture with dorsal root ganglia cells to mimic the environment of the blood-nerve barrier have been reported. This paper describes a simple method for the isolation and culture of peripheral nerve vascular endothelial cells from adult rats that should facilitate in vitro studies of the blood-nerve barrier. Endothelial cells were identified by their expression of an endothelial cell marker, Factor VIII/von Willebrand factor. Their identity was further confirmed by their inability to express Thy 1.1, a fibroblast marker, and their in vitro morphology. Purity of endothelial cell cultures was ensured by a regular program of Thy 1.1 complement depletion of fibroblasts.