Background: Mechanical ventilation is a form of life support technology used to perform the work of breathing for children who are unable to do this on their own .Thus providing adequate nursing care for children on mechanical ventilation is the most contribution to the successful management and outcomes. Aim of the study: Assess nurses' knowledge regarding care Provided to children on mechanical ventilation. Subjects and Methods: Research design: A descriptive design was utilized to conduct this study. Setting: The study was convoyed at Pediatric Intensive Care unit at Al -Ahrar Educational Zagazig Hospital, General Zagazig hospital and Zagazig University Hospital. Subjects: A convenient sample of 60 nurses. Tools of data collections: Structured questionnaire interview to assess nurses' knowledge regarding care provided to children on mechanical ventilation. Results : Revealed that two thirds of studied nurses had poor knowledge and there was highly statistically significant relation between nurses` total knowledge score and their qualifications and years of experience in a PICU. Conclusion: Studied nurses had poor knowledge regarding care provided To children on mechanical ventilation. Recommendation: Based on the results of the present study in –service training programs should be developed for nurses directed toward all aspects of care provided for children on mechanical ventilation. Key words: Nurses' Knowledge, Care, Children, Mechanical Ventilation