The research aims at examining the impact of transformational leadership on job performance. Moreover, the research explores the mediating effect of High-Performance Work System (HPWS) in the relationship between transformational leadership and job performance. A purposive sample of 400 respondents from Omani service organizations was selected for the study. The results show that transformational leadership has a positive and significant impact on HPWS and job performance. Moreover, HPWS also has a positive impact on job performance. Partial support has been found for the hypothesized mediator role of HPWS in transformational leadership and job performance relationship.