Background: Triage is a dynamic and ongoing process that is performed to allocate the patient in the right place at the right time to receive the right level of care along with the allocation of appropriate resources to meet the patient's emergent medical needs. Aim of the study: The study aimed to evaluate the effect of educational program on the nurses' triage competency for emergency patients. Research design: A quasi-experimental research design was utilized. Setting: The study was conducted in the emergency department, Benha University Hospital. Subject: Purposive sample of 50 nurses of both sex who providing care in the emergency department. Tools: Two tools were used, tool I: Self-Administered Questionnaire, composed of three parts; (1) Demographic characteristics of nurses (2) Nurses' Knowledge Assessment Questionnaire (3) Nurses' attitude regarding triage and tool II: Nurses' practice observational checklists. Results: The total mean of nurses' knowledge, attitude, and practice improved from 18.54 ± 5.86, 51.48 ±15.58, and 177.2 ± 34.54 respectively pre-educational program implementation to 31.82 ± 2.34, 78.08 ± 5.34, 344.7 ± 37.59 respectively post educational program implementation with significant difference at p = <0.001. Conclusion: Total nurses' knowledge, attitude and practice improved post educational program implementation with a significant difference and positive correlation between the nurses' knowledge and practice, knowledge and attitude, as well as between their practice and attitude post educational program implementation. Recommendations: A designed and developed Nursing Protocol between the Ministry of Health and Population and the Ministry of Higher Education to provide regular practical courses related to triage such as annual competency among the team in ED.