BACKGROUND Regional blocks have been shown to decrease the requirement of anesthetic agents. This study was conducted to determine the optimal endtidal concentrations of desflurane for removal of Laryngeal mask airway in children in presence of caudal block. METHODS Twenty-two children of ASA status I between the age group of 2-10 year undergoing infraumbilical surgery were enrolled in the study. General anesthesia was induced with sevoflurane and oxygen given via mask and laryngeal mask airway inserted. Caudal injection of bupivacaine 0.25%, 1 ml·kg(-1) was administered according to Armitage regimen. Desflurane was used for maintenance of anesthesia. Predecided endtidal concentration of desflurane was maintained for 10 min at the end of surgery and laryngeal mask airway removed. Target concentration in the next patient was thereafter determined by the Dixon up-down method (with 0.5% as a step size). 5% endtidal concentration was kept as the starting concentration. If removal of laryngeal mask airway was not associated with any coughing, teeth clenching, gross purposeful movement, breath holding or laryngospasm, during or within 1 min after removal, it was considered as successful. RESULTS In the presence of caudal analgesia, endtidal concentration of desflurane required for successful laryngeal mask airway removal in 50% (ED50) children was 3.39 ± 0.38% by Dixon's method. CONCLUSIONS Laryngeal mask airway can be successfully removed in 50% of anesthetized children without coughing, moving, or any other airway complications at an endtidal desflurane concentration of 3.4% in the presence of caudal analgesia.