The success rate and occurrence of adverse effects are reported in a retrospective study of 750 caudal analgesias in children. In 94% of the patients, the blocks were performed under light general anesthesia. Standard 1M or short-beveled needles were used in all. Four anesthetic solutions of lidocaine and/or bupivacaine with 1:200,000 epinephrine were injected in volumes ranging from 0.5 to 1.25 ml/kg. The overall success rate of caudal blocks was 96%, but several attempts were necessary in 25% of patients. Most failures occurred in children more than 7 years old. The use of short-beveled needles considerably decreased the number of traumatic punctures. The upper limit of analgesia varied widely and appropriate distribution of anesthesia was reliably obtained only after the injection of 0.75 to 1.0 ml/kg of local anesthetic solution. Conscious children tolerated surgery poorly (from a psychological point of view) although they were free of pain. Conversely, breathing difficulties occurred in 12% of lightly anesthetized patients. Hemodynamic disturbances were infrequent, as were adverse effects except for postoperative vomiting (17%). Motor block, present in 54% of patients, was poorly tolerated postoperatively by 10% of patients. Long-lasting postoperative pain relief was usually obtained. There were no major complications or neurological sequelae and good patient and parental acceptance of caudal anesthesia. Caudal anesthesia is a reliable and safe technique in young children.