The aim of this study is to examine the role of high performance work system (HPWS) in increasing performance of the employees. It further explores the mediating role played by organizational citizenship behavior (OCB) and organizational commitment in HPWS and performance relationship. A purposive sample of 330 respondents from telecom sector of Pakistan is selected for the study. The results reveal the fact that HPWS has a strong positive impact on performance. The hypothesized mediating roles of organizational commitment and organizational OCB are also partially supported. Implications and future research are also discussed.