Research on the firm's heterogeneity is a well-developed concept in the export context; literature can found in the export context. Previous research can found on firm heterogeneity and firm performance, but they are in export context. On the other hand, importing firms' heterogeneity is less sought in the literature, which we believe as a clear gap in the export-import research stream. Limited research has done in the context of importing firms. The purpose of our thesis is to explore the different forms of heterogeneities that Pakistani importing firms' practices are gaining a competitive advantage. Furthermore, our goal is to examine the extent of heterogeneity dimensions to what contributes to their performances. There is a significant gap in the research field of import. As there is less research in the import context, this will be a fundamental goal of research towards firms' heterogeneity and the importance of a country.