Objective: This study aimed to evaluate the effects of pulmonary surfactant (PS) combined with high-frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation (CMV) in infants with acute respiratory distress syndrome (ARDS) after congenital cardiac surgery.Method: A total of 61 infants with ARDS were eligible and were randomized to the CMV + PS group (n= 30) or the HFOV + PS group (n= 31) between January 2020 and December 2020. The primary outcomes were the improvement of the arterial blood gas analysis. The incidence of mechanical ventilation duration, length of hospitalization, and the incidence of complications were considered as secondary outcomes.Results: A total of 61 infants completed the study. In HFOV + PS group, the blood gas analysis results were significantly improved (P<0.05), while, duration of mechanical ventilation and length of hospitalization were shorter than CMV + PS group (P<0.05). But the incidences of complications had no statistical significance between the two groups (P>0.05).Conclusions: Compared with the CMV + PS group, HFOV + PS significantly improved the ABG variables and shortened the length of hospitalization and mechanical ventilation in infants with ARDS after cardiac surgery.