SUMMARY
Organizational citizenship behavior(OCB) and Proactive Environmental strategy are voluntary, organizatiomally desirable action that are not part of the employee’s formal job requirements but they are essential for organizatioms to remain competitive. This article investigate the effect of organizational citizenship behavior on proactive environmental strategies. This research is an applied research and data collection is based on a descriptive and survey research. The structural equations have been used to analysis the relation between variables. Statistical population of this research has been chosen from the emergency medicine students in Iran University. The sample selected with Cochran formula is about 79 persons. Data was analyzed by SPSS software. The results of this research are demonstrating that the positive and significant relationship exists between the organizational citizenship behavior and proactive environmental strategy and hospitals can increase proactive practices through organizational citizenship behavior. Therefore, hospital management should develop some practices(such as promotion, training, recognition, etc.) that can promote organizational citizenship behavior and proactive environmental strategy.