Current techniques of sciatic nerve block are blind, and nerve localization can be frustrating and time consuming. Ultrasound-guided subgluteal sciatic nerve block is performed with low-frequency scanning probes (2-5 MHz) to identify the sciatic nerve in the subgluteal space and guide the needle advancement to target nerves before injection of the local anesthetic. This technique is compared with the use of a nerve stimulator in pediatric surgical patients.