Purpose The importance of psychological capital (PsyCap) and perceived organizational support (POS) have been identified over the years, however, the underlying relationship of both constructs with different employee outcomes is still a subject of research. The purpose of this study is to investigate whether POS helps in mediating the effect of PsyCap on employee engagement (EE). Design/methodology/approach In total, 420 samples (middle-level information technology (IT) professionals) were collected from different IT industry located in India by using online survey questionnaires. The collected data were further analyzed using regression analysis, factor analysis, structural equation modeling, reliability and validity analysis, mediation analysis and model fit indices analysis. Findings The results of the present study confirmed the full mediating effect of POS on the PsyCap-EE relationship and demonstrated that employees with a higher level of PsyCap, contribute more positively to the POS level which further enhances the employee's level of engagement at the workplace. Research limitations/implications The samples collected for the current study included only middle-level IT professionals of the IT industry in India; therefore, the present study results have limited general applicability. The results and findings of the current study are only on the basis of inferential statistical analysis, and descriptive analysis was not performed on the collected data. Further, the study does not investigate the influence of time. Practical implications This study would assist practitioners of human resources in organizational development by enhancing the employee's positive attitude and commitment toward their study. Further, EE can also be improved by enhancing the levels of POS and PsyCap of employees, which is in line with the findings of the current study. Originality/value The current study examines the mediating effect of POS on psychological capital and EE the relationship for the first time.