Heretofore the insertion of arteriovenous shunts using local infiltration has been made difficult by the occurrence of vascular spasm. The changing caliber of the vessels has resulted in leakage and diminished flow at the shunt, necessitating frequent revisions. To obviate these difficulties and to permit more adequate cannulas to be employed, blocking of the brachial plexus was initiated. This technique, using the axillary approach, was undertaken on 30 cases. The resultant vasodilation and analgesia facilitated surgery appreciably. Infrared photography and thermographic examinations substantiating the clinical findings were done. Axillary block of the brachial plexus is regarded the method of choice for this procedure, providing excellent working conditions for the surgeon with a minimum of risk and discomfort for the patient.