Pneumonia is an inflammation and consolidation of lung parenchyma. The aim of the current study was to determine the impact of implementing protocol of care for childhood pneumonia on nurses' knowledge and practice. A quasi-experimental study was used and carried out at pediatric wards of El-Nasr, Port SaidGeneral, and Port-Fouad General Hospitals. The subjects were comprised of 44 nurses and 25 children with pneumonia. The data was collected using an interview questionnaire sheet to assess nurses' knowledgeand observational checklists to assess nurses' practice as well asa data sheet of children with pneumonia. The study's results indicated thatmore than half of them had an average knowledge scores level before application of the protocol; but immediately after implementation of the protocol, a vast majority of the studied nurses had good level; meanwhile after 12 weeks (follow up), three-quarters of them had good level. Regarding nurses' level of practice(100%)of the studied nurses had poor level in pre test; while in post test the majority of them (84%) had good level regarding their level of practice and after 12 weeks as a follow- up 95.5%of them had average level. The study's results concluded that the designed protocol of care regarding childhood pneumonia had highly statistical significant differences in the studied nurses' knowledge and practice. The study recommended that periodic refreshing training courses should be provided to nurses in order to keep them up to date in knowledge and practice regarding care of childhood pneumonia.