Background: One of the behaviors taken into consideration in organizations such as hospitals is organizational citizenship behavior. Recent studies have shown that organization employees show interest in organizational citizenship behavior and this subject may be influenced by demographic specifications.This study aims to determine the relationship between organizational citizenship behavior and demographic specification (gender, age, marital status, educational qualifications, salary&wage ,ethnicity,employment type, work type, organizational post, place of employment and work experience) among selected hospitals employees of selected hospitals of Tehran and Shahid Beheshti Medical Sciencesis Universities. Materials and Methods: This research has been implemented in six selected Hospitals of Tehran and Shahid Beheshti Medical Sciencesis Universities and data was collected by distributing a questionnaire among 429 employees of these hospitals using a two-stages random sampling method.The research methodology has been cross-sectional- descriptive using field study. In order to accept or reject the research hypothesis kruskal-wallis and mann-whitneyU tests have been used. Results: Results showed that, the most studied demographic characteristics have an effect on organizational citizenship behavior of the staff of selected hospitals employees in Tehran and Shahid Beheshti Universities of Medical Sciences. Conclusion: Findings of this research indicated that men have shown more organizational citizenship behavior compared to women, Married people have shown higher organizational citizenship behavior compared to single and divorced people and people in the age class of 50 to 54 years have been the highest organizational citizenship behavior average. In addition to, people with master degree, have been the highest organizational citizenship behavior. Also our findings show that Ethnicity does not have effect on the incidence of organizational citizenship behavior.
