While today's supply chains involve partners from different countries, national culture has been a critical component in supply chain management. Yet, our understanding on its role in affecting the performance outcomes of supply chain integration (SCI) is limited. Using data collected from 19 countries and the GLOBE concept of national culture, we analyze the role of national culture in affecting SCI. This paper examines how differences in national culture influence SCI operational outcomes. Our results indicate that the collaborative behavior oriented national culture dimensions of future orientation, institutional collectivism, humane orientation and in-group collectivism moderate the extent to which SCI improves operational performance. Specifically, the relationship between internal integration and quality outcomes is moderated by institutional collectivism, humane orientation, and future orientation. The relationship between internal integration and cost is moderated by in-group collectivism, while the customer integration and delivery performance relationship is moderated by institutional collectivism.