In anaesthesiology of today, due to the increased use of strong analgetics, it is necessary to have an effective antagonist for mini- mizing the danger of respiratory depression in postoperative ...period. Naloxone, ( Narcan , R-Endo Laboratories Inc., Subsidiary of E. J. du Pont de Nemours and Co., (Inc.), USA), a new narcotic antagonist was investigated in this study. It has been applied to 58 patients in cases of respiratory depression at the end of anaesthesia in which fentanyl was given, (these cases constituted 14% of all anaesthesias). Fentanyl was given intravenously in fractional doses, (fig 1), during NLA, and other general anaesthesias, for operation and diagnostic examination ( exeption of cardiosurgery), in children and adolescents from two month-to nineteen years of age, (tab. 1.). Naloxone was given intravenously, in fractional doses from 1 microgram to 5 micrograms/kg body weight. As a criterium of an antidepressive effect of Naloxone--in addition to clinical evaluation, blood gases analyses and continuous capnographic recording has been accepted. In all 58 cases diminition of respiratory depression was observed 2-3 min. after injected each dose of Naloxone. Respiratory rate increased from 15 to 22/min. concentration of CO2 in expired gases decreased from 5-6% to 4,5%, (fig. 2 and 3), and regain of consciousness, and return of intensive reaction to endotracheal tube stimulation was observed. Naloxone produced neither changes in the cardiovascular system, nor side effects. Based on these results Naloxone has been suggested as an effective narcotic antagonist. It increase of the possibility of applying strong analgetics in children--allowing to keep a steady level of anaesthesia with easy elimination respiratory depression in the desired period of time.