Ventilator-associated pneumonia (VAP) is a nosocomially acquired infection that has a significant burden on intensive care units (ICUs). We investigated the incidence of VAP in children after cardiac surgery and its impact on morbidity and mortality. A prospective cross-sectional review was performed in the postoperative cardiac patients in pediatric cardiac intensive care unit (PCICU) patients from March 2010 until the end of September 2010. The patients were divided into two groups: the VAP group and the non-VAP group, Demographic data and perioperative risk variables were collected for all patients. One hundred thirty-seven patients were recruited, 65 (48%) female and 72 (52%) male. VAP occurred in 9 patients (6.6%). Average body weights in the VAP and non-VAP groups were 5.9 ± 1.24 and 7.3 ± 0.52 kg, respectively. In our PCICU, the mechanical ventilation (MV) use ratio was 26% with a VAP-density rate of 29/1000 ventilator days. Univariate analyses showed that the risk variables to develop VAP are as follows: prolonged cardiopulmonary bypass (CPB) time, use of total parenteral nutrition (TPN), and prolonged ICU stay (p < 0.002 for all). Thirty-three percent of VAP patients had Gram-negative bacilli (GNB). VAP Patients require more MV hours, longer stay, and more inhaled nitric oxide. Mortality in the VAP group was 11% and in the non-VAP group was 0.7 % (p = 0.28). VAP incidence is high in children after cardiac surgery mainly by GNB. VAP increases with longer CPB time, administration of TPN, and longer PCICU stay. VAP increases morbidity in postoperative cardiac patients.