Abstract: An effective Supply Chain Management (SCM) has been increasingly recognized as critical factors in gaining competitive differentiation and enhancing SCM performance. More and more firms are increasingly implementing SCM to improve their competitive performance. In order to understand the connection of SCM and the performance of an organization, this study looks into consideration of many arguments from various research papers. This study presents, the findings of a research which examines the relationship between SCM, product quality and competitive differentiation determinants of the manufacturing companies in Malaysia. The study measures perception of senior management regarding the SCM practices and the level of product quality and competitive differentiation measurements in their companies. The associations between SCM, product quality measurements and competitive differentiation dimensions are analyzed through methods such as Pearson’s correlations and Smart Partial Least Square (Smart PLS) using 126 respondents’ data. The correlation results demonstrate that SCM practices have significant correlations with product quality measurements (comprises of product conformance, product durability, product performance and product reliability). The findings also suggest that SCM practices have significant correlations with competitive differentiation determinants (comprises of factors such as employee differentiation, price differentiation, product differentiation and service differentiation). Specifically, both product quality measurements and competitive differentiations have high correlations with SCM practices, namely ‘strategic supplier partnership’, ‘lean production’ and ‘postponement concept’ and ‘new technology and innovation’. The Smart PLS result also reveals that SCM practices exhibit significant direct impact on both product quality measurements and competitive differentiation indicators. The findings of the study provide a demonstration of the importance of SCM practices in enhancing competitive performances in Malaysian manufacturing companies. This study contributes to the literature of supply chain management by exploring the critical SCM variables and also investigating the relationship between the SCM and performances in manufacturing companies.