The purpose of this study is to investigate the mediating role of psychological well-being between psychological capital and organizational citizenship behavior. To achieve the objectives of this study, data has been collected using a survey method through a cross-sectional technique from employees (n =199) working at higher education institutes in Pakistan. The Preacher and Hayes (2008) method of bootstrapping has been employed by using the Process macro for SPSS. The results of the analysis indicated that psychological well-being works as a mediating mechanism between psychological capital and organizational citizenship behavior. The critical flow-on effects of this study are that it has both theoretical and practical implications in the workplace. Therefore, the logical connection is that this study has filled the gap in the literature by testing the mediating role of psychological well-being in the link between psychological capital and organizational citizenship behavior. Apart from the theoretical implication, there are practical implications of the resulting analysis for practitioners, especially those in higher management of education institutes who are keen to see extra-role behaviors displayed in their staff. The authors have also discussed the limitation and future direction of the study, which will help future researchers to extend this study.