Primary nerve grafting should be considered whenever tumor extirpation necessitates resection of an adjacent critical nerve. A technique of nerve grafting is presented which distinguishes motor from sensory fascicles, using intraoperative electrical stimulation. Stimulation of individual motor fascicles is performed proximal and distal to the lesion, and fascicles which produce the same muscle contraction are identified. Motor and silent sensory fascicles are tagged prior to tumor resection. This facilitates subsequent specific motor/sensory reconstruction of the defect, using intrafascicular grafting techniques.