This study examines the model that connects the High performance work system (HPWS) with employee attitude. The researcher proposed that there is mediating role of HR flexibility between HPWS and employee attitude. The sample of (N=223) employees working in three Telecom organizations of Faisalabad region was used to analyze the data. A High Performance Work System (HPWS) comprises of a set of important HRM practices which may satisfy the employees, enhance employee’s retention, increase organizational commitment & controlling over turnover intention/ratio was developed. The impact of HPWS was examined on employee attitude by taking the human resource flexibility as mediating variable. The model was statistically tested by using regression analysis and preacher technique. The results depicted that HPWS influenced employee attitude (OC, JS, and TOI) through HR flexibility (behavior flexibility Functional flexibility and Skill malleability). HPWS is positively related to individual’s job level attitudinal factors i.e. turnover intention (TOI), organizational commitment (OC) & job satisfaction (JS). The 24% proportion of variance of OC, 63% of job satisfaction and 18% TOI is explained by the independent variables. HPWS explained 29% portion of employee’s attitude. Some well-known theories; social exchange theory, cognitive dissonance theory, human capital theory, three component theory of organizational commitment and resource based view support the results of current study.