Current techniques of brachial plexus block are blind, and nervelocalization can be frustrating and time consuming. Ultrasound-guidedaxillary brachial plexus block is performed with multi-frequencyscanning probes (6-13 MHz) to identify the brachial plexus and guidethe needle advancement to target nerves before injection of the localanesthetic. This technique is compared with the use of a nerve stimulatorin pediatric surgical patients.