Objective: to study the safety and clinical and economic efficiency of early activation of children operated on under extracorporeal circulation (EC). Subjects and methods. Sixty-eight children aged 4—14 years (8.6±0.4 years) operated on under EC for congenital heart diseases (CHD) were examined. In accordance with the time of switching to spontaneous respiration and tracheal extubation, 2 groups were identified: 1) those who received postoperative artificial ventilation (AV) for 2.9±0.2 hours (a study group); 2) those who had AV for 8.7±0.7 hours (a control group). Both groups did not differ in age, cardiac diseases, their severity, anthropometric characteristics, EC duration, aortic ligation time, and abnormality pattern. In the study group, anesthesia was maintained with fentanyl (5.3±0.1 ^g/kg/hr), diazepam (0.15±0.01 mg/kg/hr), and inhaled ftorotan or enflurane. Diazepam was discontinued in the postperfusion period. The control group received fentanyl (7.6±0.4 ^Bg/kg/hr), diazepam (0.3±0.02 mg/kg/hr), droperidol (0.4±0.04 mg/kg/hr), and/or sodium oxybutyrate (81±5 mg/kg/hr). Myoplegia was provided by pancuronium or pipecuronium that was continuously infused until EC was completed in Group 1 and intermittently injected until the end of surgery in Group 2. Results. There were no indications for tracheal reintubation in both groups of patients. The early postoperative period was uncomplicated in 97.2% of the children in the study group and in 28.1% in the control group (p<0.05). The incidence of pulmonary complications was 2.8 and 46.9%, respectively (p<0.05). In the children from Groups 1 and 2, the duration of a resuscita-tive period was 44.2±1.7 and 77.3±4.9 hours, respectively (p<0.05), and that of the whole postoperative period was 12.6±0.3 and 18.0±1.1 days (p<0.05). In the study group, the total final expenditures, including the cost of anesthesia and treatment for postoperative complications, decreased by 127.5% as compared to the control group (p<0.05). Conclusion. Early activation causes a substantial reduction in the number of pulmonary complications and in the duration of all postoperative treatment stages in children with CHD, which permits the cost of cardiosurgery to be significantly decreased under the conditions of a regional clinical hospital. The procedure of total anesthesia that provides activation within 6 hours may be based on the use of the least expensive drugs (fentanyl, diazepam, ftorotan, pancuronium or pipecuronium). Key words: early activation, artificial ventilation, congenital heart diseases, pulmonary complications, cost effectiveness.