The authors reviewed 52 patients who underwent Bier's block, as supplementary anesthesia for insufficient axillary block in upper extremity surgical procedures. Prior to proceeding to the Bier's block, the mean value of pain using the visual optical analogue scale (VAS) was 7.0. In 48 of the patients supplementation with the Bier's block was sufficient (mean VAS score of 1.0) and all patients were comfortable throughout the procedure. In the remaining four patients supplementation with narcotics and sedatives via the other i.v. line was required. Intraoperative Bier's block provides a safe and effective alternative way of successfully compensating for an insufficient axillary block in upper extremity surgical procedures.