The aim of the study was to evaluate the effect of guideline protocol regarding COVID-19 preventive measures on practice of hospitalized school age children. One group pre-posttest quasi-experimental design was conducted on sample of 72 hospitalized school-aged children at Zagazig University Pediatric Hospital. Two Tools were used; first a Structured Interview Questionnaire to collect data about studied children characteristics and evaluate their awareness regarding COVID-19 and the second tool was checklist to evaluate studied children practice regarding COVID-19 preventive measures. The results revealed that 12.5% of the studied group had satisfactory practice level regarding COVID-19 preventive measures before the guideline protocol compared to 95.8% post the protocol (P<0.001).