Introduction: In recent decades, with the entrance of new concepts such as spirituality in work place, spirituality seeking in work, work values, ethics, sense giving to organization, a new paradigm was introduced in organizations that can work as spirituality in workplace. Studies show that organizations using Spirituality in Workplace, achieve high levels of growth and development in Organizational Citizenship Behavior. Therefore, the main purpose of this paper is to investigate the relationship between the Employees` Spirituality in Workplace and Organizational Citizenship Behavior at Shiraz University of Medical Sciences.
 Methods: Research method was descriptive-correlative. To collect data, 260 employees at Shiraz University of Medical Sciences were surveyed. Research instruments were to questionnaires: 1) Organ’s Organizational Citizenship Behavior (1989), and 2) Milliman et al (2003) ` Spirituality in Workplace. Reliability coefficients were.71 and .82 respectively, using Chronbach’s formula. The collected data were analyzed using one- sample t-test, Pearson correlation, and multiple regressions.
 Results: Findings showed that there are a positive and significant relationship between Spirituality in Workplace and its components with Organizational Citizenship Behavior .T test results showed that Spirituality in Workplace and Organizational Citizenship Behavior are in a rather good status. The regression result showed that only the impact of the Community as component of Spirituality in Workplace on Organizational Citizenship Behavior was found to be meaningful.
Conclusion: According to the findings, it can be suggested that the existence of Spirituality in Workplace can result in the improvement of Organizational Citizenship Behavior.