In recent years, volunteers as auxiliary forces for human resources have been playing a vital and effective role to mitigate the effects of disasters (1). Volunteers need to be recognized, guided, and prepared by the relevant agencies and organizations. Volunteers are considered a valuable resource for the community, especially when they are trained and given missions properly under the existing management system (2). According to comprehensive theory of volunteers, volunteerism is productive and profitable. Undoubtedly, among the multiple institutions and organizations related to disaster and rescue management, healthcare systems, particularly hospitals, are the main unit of providing services in disasters (3). Hospitals are faced with shortages of nursing and rescue forces in disasters (4). Also, there is the possibility of damage to the hospital and the staff during unexpected events. In such situations, the existence of volunteers' management in hospital is essential for improving the performance of healthcare systems. Previous studies have investigated the volunteers in the red crescent in Iran; however, the innovation of this study is to discuss the activities of the volunteers in hospitals. The weakness in the volunteers' preparation by the healthcare systems causes irreparable damages after the disasters. Hospitals require programs and plans to prepare the volunteers in three phases of the disasters (before, during, and after). For this purpose, it is necessary to identify and prioritize the measures and the activities at each stage. The aim of this study was to examine the preparation measures of the local volunteers in hospitals (before, during, and after) disasters.This was a cross sectional study in which a researchermade questionnaire was used to collect the data in September 2014 to May 2015. The population was composed of all relief and rescue managers, emergency nurses, and emergency doctors in the hospitals of Tehran University of Medical Sciences (governmental hospitals). A total number of 180 participants were selected by random sampling method. The questionnaire consisted of 30 items in 3 domains as it follows: 1) before disaster (9 items); 2) during disaster (10 items); and 3) after disaster (11 items). The items were rated according to a 5-point scale from 1 to 5. Cronbach's alpha was used to assess the reliability. Cronbach's alpha was calculated for the three sections of the questionnaire (0.75, 0.81 and 0.79). Calculated Cronbach's alpha indicated that the questionnaire had acceptable reliability.The data have been analyzed using mean ± SD, one-sample t-test, and Friedman test. One-sample t-test was used to analyze the significance of the volunteers' preparation measures. Friedman test was used to prioritize the preparation measures.The results of the t-test showed that all the preparation measures in the three phases of the disasters were significant (P ≤ 0.05). The priority of the preparation measures before disaster included maneuver (mean rank = 6.61), holding practical tests (6.05),...