Ventilator associated pneumonia is an ongoing iatrogenic burden within the healthcare system for pediatrics .so most of critically ill children experience Ventilator Associated Pneumonia and it is the most fatal of hospital acquired infections, with high mortality rates. Nurses play a serious role in prevention of it by adherence to infection preventive measures. This study aimed to assess nurses' knowledge and performance regarding infection preventive measures of ventilators associated pneumonia Method: Across section study design was utilized. Setting: The study was conducted at Pediatric Cardiac Intensive Care Unit at Mansoura University Children Hospital (MUCH). Tool I: Nurses' socio demographic and occupational characteristics self-administrated questionnaire. Tool II: Nurses' knowledge self-administrated questionnaire to examine nurses’ level of knowledge regarding infection preventive measures for VAP. Tool III: The researcher developed this observational checklist to assess nurses' level of performance regarding infection preventive measures for VAP. Results: the current study indicates that, 90% and 96.7% of the studied nurses have poor total knowledge scores level and classified as beginner with total performance score level respectively regarding VAP infection preventive measures. Conclusion: The study concluded that, most of studied nurses have poor total knowledge score level regarding VAP infection preventive measures. Concerning studied nurses' total performance score level about VAP infection preventive measures, ventilator care measures, suction care, oral care and preventive measures for peptic ulcer and deep vein thrombosis, score level of most of them were classified as beginner. Recommendation: develop and implement on job training sessions for newly hired nurses regarding VAP infection preventive measures.