Introduction: The key to successful management of large number of victims with limited resources is triage, which without preparedness of nurses seem to be impossible. The aim of this study was to determine the effect of simulated training course on preparedness of nurses to do pre-hospital triage at Razi psychiatric hospital.

Materials and Methods: This is a quasi-experimental study on 60 nurses in Razi psychiatric hospital who according to the inclusion criteria and randomly divided into two experimental and control groups equally by 30. The study tools developed by the researcher included “Knowledge of Disaster Triage Test” that contains 30 questions of four-choice. The “Accuracy of Disaster Triage Test” also contains 30 questions with four-choice. Face validity and content validity has been evaluated. Reliability were evaluated using Cronbach’s alpha for the “Knowledge of Disaster Triage Test” 0.75 and for the “Accuracy of Disaster Triage Test” 0.78. A day workshop “Disaster Triage Simulation Method” was arranged for intervention group and two groups were assessed by study tools before and after intervention. Data were analyzed using SPSS/16.

Findings: The mean score of nurses preparedness regarding triage training (Knowledge and accuracy) in the intervention group were significantly different before and after the intervention (p<0.001). The mean difference of nurses preparedness triage training (Knowledge and accuracy) there were significantly different between the two groups respectfully (p<0.001).

Conclusion: The results of the study showed, using the simulation method on triage training improved the nurses preparedness to do disaster triage. Therefore it is recommended to do this training program for nurses’ to improve their preparedness for disaster triage.