This paper aims to investigate the role of mediating organizational citizenship behavior in impact of gender leadership styles on workforce performance in Palestinian public sector. Data was collected by distributing questionnaires on leaders in Palestinian public sector. Using Multi-group structural equation modeling (SEM), the paper finds several results; female transformational leadership style had a positively significant direct impact on with workforce performance, also male transformational leadership style has positively significant direct impact on organizational citizenship behavior in the Palestinian public institutions. Moreover, there is no direct impact of male transactional and Laisses-faire leadership styles on organizational citizenship behavior. In female leadership styles, results show that female transformational, transactional, and Laisses-faire leadership styles are positively significant direct impact on organizational citizenship behavior in the Palestinian public institutions. At the end, organizational citizenship behavior is not significant direct impact on workforce performance in the Palestinian public institutions for both male and female leaders. Key Words: Gender Leadership Styles, Organizational Citizenship Behavior, Workforce Performance, Palestinian Public Institutions.