A group of 42 consecutive cases were exactly examined before surgery. The occurrence, the location, and the irradiation of the Tinel sign was repeatedly registered. There were cases which did not show a Tinel sign, there were cases with a positive Tinel sign irradiating towards the neck and the auricle. There were cases with a positive Tinel sign irradiating into the arm, corresponding to the skin territory of a spinal nerve. The hypothesis was that no Tinel sign speaks for root avulsion, a positive Tinel sign with radiation outside of the extremity speaks for a lesion of the cervical plexus, and a positive Tinel sign with irradiation into the territory of a spinal nerve is a strong argument that at least one root is not avulsed. The intraoperative findings were carefully analyzed and compared to the prediction of the study of the Tinel Hoffmann sign. The result was that a negative Tinel sign is not conclusive. A positive Tinel sign, however with radiation in a certain area corresponded in all cases with the operative findings. A positive Tinel sign, therefore, is a strong argument that at least one root is not avulsed.