Objective To evaluate the occurrence, risk factors and pathogen distribution of ventilator-associated pneumonia (VAP) in children with congenital heart disease (CHD) in the cardiothoracic surgical intensive care unit (CICU). Methods CHD pediatric patients who underwent surgical treatment and developed postoperative VAP in the CICU of a hospital from January 1, 2017 to December 31, 2022 were selected as the research subjects. The incidence, risk factors, and pathogen distribution characteristics of postoperative VAP were analyzed. Results A total of 677 pediatric patients were enrolled in the study. The duration of mechanical ventilation was 2 546 days. 51 patients developed VAP, and the incidence of VAP was 20.03‰. Univariate analysis showed that the incidence of postoperative VAP was higher in CHD pediatric patients who had no preoperative pulmonary infection, with pulmonary arterial hypertension, longer duration of extracorporeal circulation, and emergency or sub-emergency surgery, with statistically significant differences (all P < 0.05). Among the 25 pediatric patients with positive pathogenic culture, 27 strains of pathogens were isolated, including 24 strains (88.89%) of Gram-negative bacteria, mainly Klebsiella pneumoniae (n=8), Pseudomonas aeruginosa (n=5), and Escherichia coli (n=4). Two strains (7.41%) were Gram-positive bacteria, both identified as Staphylococcus aureus. One fungal strain (3.70%) was Candida albicans. Conclusion The incidence of postoperative VAP in CHD pediatric patients is high. Pulmonary arterial hypertension, duration of extracorporeal circulation, emergency surgery, and pulmonary infection are closely related to VAP.