This study intended to examine the effect of information technology (IT) investment and corporate governance mechanism on the performance of the Saudi telecommunication sector with mediating role of corporate social responsibility (CSR). A survey method was used to collect data from the targeted Saudi telecom firm. Results show that corporate governance practices, i.e., internal audit, internal audit committee, and internal board size, have a significant and positive relationship with firm performance. Furthermore, IT investment positively affects the performance of Saudi telecommunication firms. Moreover, CSR mediates the relationship among internal audit, internal audit committee, internal board size, IT investment, and firm performance. This study contributes to the body of knowledge regarding IT investment, corporate governance mechanism, corporate social responsibilities, and firm performance of telecommunication firms in emerging markets. Furthermore, this study will help the top management of the telecom firms to improve corporate governance and IT investment, which will be beneficial to enhance firm performance.