Purpose: The purpose was to investigate the relationship between servant leadership and teachers' organizational citizenship behavior with mediating role of psychological empowerment. Research Methods: This study was an applied and correlation research method based on structural equation modeling. 281 teachers of Zahedan city were studied by stratified random sampling method. To collect information, three questionnaires were used: servant leadership (Gholipur et al., 2009), organizational citizenship behavior (Podsakoff & MacKenzie, 1990) and psychological empowerment (Spreitzer, 1995). For data analysis the Pearson correlation coefficient and structural equation modeling were used. Findings: The amount of correlation coefficient of servant leadership with psychological empowerment (r=0.616, p<0.01), servant leadership with organizational citizenship behavior (r=0.667, p<0.01), and psychological empowerment with organizational citizenship behavior (r=0.724, p<0.01) was significant. The direct effect of servant leadership on organizational citizenship behavior ([beta]=0.27, t=3.96), direct effect of servant leadership on psychological empowerment ([beta]=0.71, t=9.72), and direct effect of psychological empowerment on organizational citizenship behavior ([beta]=0.67, t=8.03) was significant. The indirect effect of servant leadership on organizational citizenship behavior was also significant with the mediator role of psychological empowerment ([beta]=0.475). Implications for Research and Practice: Therefore, it can be concluded that servant leadership has a positive and significant relationship, directly and indirectly, through the psychological empowerment mediation variable with the organizational citizenship behavior.