This research examines how national cultural differences between the acquirer and target firms affect post-acquisition performance in cross-border acquisitions. We focus on two dimensions of national culture—individualism/collectivism (IDV) and power distance (PDI)—for their close relevance to structural changes that occur during post-acquisition integration. We find that while differences in PDI are negatively associated with post-acquisition performance, differences in IDV positively affect such performance. We also find that the acquirer’s cultural learning from supply chain partners helps mitigate the negative impact of PDI differences on post-acquisition performance, especially when the partner has a similar national culture in PDI to the target. Our theoretical development and empirical findings contribute to the operations and supply chain management research by illuminating the differential effects of national cultural differences on post-integration outcomes. Also, our study sheds new light on the possibility that working with supply chain partners may provide an opportunity for cultural learning that can be utilized in a post-acquisition integration setting.