Abstract： Objective To evaluate the role of using non-invasive ventilation with bi-level positive airway pressure (BiPAP) in order to reduce the need of re-intubation in pediatric patients with respiratory failure after cardiac surgery. Method From January 2007 to December 2007, 25 patients aged from three months to 11 years with median 2.3 years operated on for cardiac surgery with respiratory insufficiency after extubation and re-intubation indicated were enrolled in this study. They were put on non-invasive nasal (mask) BiPAP ventilation before re-intubation. The arterial blood gas, A-aDO2 and PaO2/FiO2 were measured. In addition, clinical data including heart rate, respiratory rate, and the product of heart rate and systolic pressure were recorded before and after BiPAP. The software SPSSD 13.0 was used to process by ANOVA test for statistical analysis. Meanwhile, the outcome of these patients was analyzed. Results Twenty-five patients with 30 episodes of respiratory insufficiency were treated with BiPAP ventilation with median duration of 1.96 days ranged from 0.03 to 12 days. Of these respiratory failure episodes, 25 ones (83.3%) could be controlled by BiPAP and the needs of re-intubation were avoided. Five episodes of respiratory failure in 4 patients could not be quelled and the endo-tracheal tubes were inserted in these patients. All patients were saved with a median of mechanical ventilation duration of 3.4 days and ICU stay of 10.6 days. No major complications were observed. The heart rate, respiratory rate and the rate-pressure product were decreased significantly one hour after BiPAP (P < 0.05 all). Meanwhile, patients showed rapid improvement of oxygenation. The pH, SpO>2 and PaO2/FiO2 were increased significantly and A-aDO2 was decreased significantly (P < 0.05 all). The PaCO2, was decreased significantly four hours after BiPAP (P < 0.05). Conclusions Non-invasive nasal mask BiPAP can be used safely and effectively in children after cardiac surgery to improve oxygenation/ventilation, decreasing the work of breathing. It may be particularly useful in patients with high risk of re-intubation.