Background: Noninvasive respiratory support is often used in preventing postextubation respiratory failure in neonates and infants after cardiac surgery. Aim: We compared the efficacy of nasal Bilevel Positive Airway Pressure (N/BiPAP) with that of High- flow Nasal Cannula(HFNC) in prevention of post extubation respiratory failure and maintenance of gas exchange in neonates and infants undergoing cardiac surgery. The incidence of complications related to the use of these modes were also compared. Settings and Design: This is a retrospective review of medical records of patients in pediatric cardiac intensive unit of a high-volume center. Methods: A total of 100 patients who received noninvasive respiratory support postextubation were divided into N/BiPAP group and HFNC group. The two groups were compared for postextubation respiratory failure, gas exchange in arterial blood gas at 24 h of extubation, and incidence of complications, namely pneumothorax, abdominal distension, and device–interface-related pressure ulcers. Results: Fifty patients each received N/BiPAP and HFNC after extubation. Patients who received N/BiPAP were younger (2.68 ± 2.97 months vs. 6.94 ± 4.04 months, P = 0.001) and had longer duration of postoperative ventilation (106.98 ± 79.02 h vs. 62.72 ± 46.14 h, P = 0.001). The reintubation rates were similar (20% [ n = 10] in N/BiPAP group vs. 8% [ n = 4] in HFNC group, P = 0.074). The mean arterial PO 2 values at 24 h of extubation was 119.17 ± 56.07 mmHg for N/BiPAP group versus 123.32 ± 64.33 mmHg for HFNC group ( P = 0.732). Arterial PCO 2 values at 24 h were similar (43.97 ± 43.64 mmHg in N/BiPAP vs. 37.67 ± 4.78 mmHg in HFNC, P = 0.318). N/BiPAP group had higher incidence of abdominal distension (16% [ n = 8] vs. nil in HFNC group, P = 0.003) and interface-related pressure ulcers (86% [ n = 43] vs. 14% [ n = 7] P = 0.006). Conclusion: N/BiPAP and HFNC have comparable efficacy in preventing reintubation and maintaining gas exchange. HFNC has fewer complications compared to N/BiPAP.