This study evaluates nosocomial infections in pediatric patients post-cardiac surgery, analyzing data from the National Center for Cardiovascular Diseases in China. Out of 4776 patients, the nosocomial infection rate was 2.1%, with multidrug-resistant organisms (MDROs) found in 36 patients. Pneumonia and sepsis were the most common infections, with pneumonia showing an incidence density of 7.2/1000 patient-days. MDRO infections were associated with significantly longer intensive care unit stays compared to non-MDRO infections. The results highlight the impact of MDRO infections on surgical outcomes and the importance of infection prevention and control measures.