Corporate social responsibility (CSR) is a growing issue in emerging markets. This study aims to evaluate the impact of CSR on firms’ performance by exploring the role of mediating variables such as corporate reputation (CR) and customers’ purchasing intention (CPI). We use the quantitative technique of Partial Least Squares Structural Equation Modeling (PLS-SEM) techniques to analyze the data of the small and medium-size enterprises (SMEs) from the Southern Vietnam in 2020. The findings suggest a positive and significant impact of corporate/ social responsibility on firms’ performance through mediating role of CR and CPI. This study contributes to the literature on corporate social responsibility and firms’ performance of SMEs in the emerging country context. The outcomes of this study can be used by entrepreneurs, top management as an attempt to boost the performance of the SMEs in emerging markets by applying CSR measures for sustainable competitive advantage. A mediating role of corporate reputation (CR) and customers’ purchasing intention (CPI) as a value-added contribution to this study.