Purpose: The purpose of this study was to develop evidence-based nursing practice guidelines for the care of febrile children in the emergency room and to evaluate the guidelines by applying them to practice. Methods: This study was conducted using a methodological design. referring to the Scottish intercollegiate guideline network, draft of guidelines were developed based on the recommendations found from the critical literature analysis. Then, the draft was modified by an expert group and a pilot application. The final draft was evaluated by the expert group using appraisal of guidelines for research and evaluation. Finally, the final guideline and algorithm were completed. Results: The guideline includes 39 recommendations for the care of febrile children in the emergency room. Conclusion: The clinical guidelines developed through this research can be utilized as systematic and scientific guidelines for the care of febrile children in the emergency room. In addition, the research results will contribute to improving care services.