To determine Whether neoatigmine had different effecta in pediatric patients and adults during vecuronium neuromuscalar blockade, the rate of recovery following neostigmine admimistration was compared in children (n=10, group I) and adulta (n=10, group II) during nitrous oxide-Halothane anesthesia. After induction of anesthesia, patients received 100 ug/kg of vecuronium. Reversal was attempted at 10% spontaneous recovery of twitdi height, Neostigmine (30 ug/kg in children, 40 ug/kg in adults) was injected in a single bolus dose. During the first few minutes following neostigmine admimistration, no differences were obaerved between the two groups, Ten minutes after neostigmine admmistration, the first twitch (mean±SD) reached 95±2%, 93±2% of control value in children and adults respectively. The more complete recovery of the eighth minutes in children could be due to the faster rate of spontaneous recovery from vercuronium induced neuromuscular blockade in children.