In today’s fast changing environment, where the globalization is taking place everywhere, it is a challenge for organizations to be remaining competitive in market. Human capital is one of biggest source of competitive advantage for organizations that cannot be easily imitated by other organizations while other capitals like structural or financial capital can be copied easily. In todays’ era, the pace of interest in human capital, social capital and organizational performance is gaining momentum around the globe. Impact of human capital on organizational performance has been tested. Mediating role of social capital in between human capital and organizational performance has also been tested; but moderating role of social capital in between human capital and organizational performance is still under-examined phenomenon. Therefore, this thesis provides an original contribution to the existing literature. This study contributes to the existent literature by investigating the impact of human capital on job satisfaction, career satisfaction and life satisfaction of employees which are important indicators of organizational performance in service sector of Pakistan; especially banking and education industry. Moderating role of social capital in between human capital and organizational performance is also tested. Data has been collected through structured questionnaire and interviews from faculty memberofuniversities, and officer grade rank employees of banking industry from five major cities of Punjab, Pakistan. Different statistical tools such as Correlation analysis, Confirmatory factor analysis, Structural Equation Modeling and Hierarchical Regression Analysis have been applied for analyzing the data. The findings of the study provided considerable support for the hypothesized relationships between overall human capital and organizational performance. Regarding moderating effects, the results provided strongsupport for hypothesis that social capital does moderate the relationship between human capital and organizational performance. This thesis opens new horizons of future research.The findings have significant implications for service sector.