Background: Nurse Interns' knowledge, practice regarding triage and adherence to preventive behaviors has been influential factors in triage decision-making at emergency units during COVID 19 Pandemic. Aim of the study: Enhancing nurse interns` knowledge and practice regarding triage at emergency units during COVID 19 pandemic. Design: A quasi experimental design was utilized in this study. Setting: Emergency Units at Benha University Hospital. Subjects: A convenient sample of 60 nurse interns. Tools for data collection: Intern Nurses` Personal Characteristics Sheet, Nurse Interns` Knowledge Questionnaire, Triage Practice Observational Checklist, COVID-19 Preventive Behavior Assessment Tool. Results: Nurse interns' knowledge, practice regarding triage was highly statistically significally improved after the program implementation. Also, their preventive behavior regarding COVID-19 level was highly statistical significant improved after the program implementation. As (72.7%) of them had poor preventive behavior level, that improved to (86.6%) had good preventive behavior level post program. Conclusion: the triage program had a significant effect on improving nurse interns' knowledge and practice of triage, and total preventative behavior regarding COVID-19 level was significantly improved after the program phase. Recommendations: Publication and dissemination of the educational guidelines in emergency department service to improve nurse interns' performance about triage corona virus patients.