Using data collected from 277 buyers employed at large purchasing organizations (LPOs) in the U.S. and U.K., this study investigates factors that might influence their willingness to procure goods and services from ethnic minority businesses (EMBs). The social capital literature is used to develop hypotheses concerning the cognitive, structural, and relational dimensions that may play roles in decisions to buy from minority firms. Subsequently, modern discrimination theory is employed to provide inductive insights into how buyers' attitudes toward supplier diversity mediate the effects of social capital on their procurement activities with EMBs. The results of multiple regression analysis suggest that in both the U.S. and U.K., positive social capital as perceived by the buyers has a direct, significant relationship with their expenditures with EMBs. The results also reveal that in both countries, buyers' attitudes toward supplier diversity mediate the relationship. Interestingly, although the U.S. originated the concept of supplier diversity, our research uncovers that U.K. LPO buyers have greater expenditures with their EMBs. Based on these findings, this research illustrates how strategic corporate social responsibility initiatives set forth by LPOs may be impacted by their buyers' social relationships with EMBs and their attitudes toward supplier diversity.