The essence of market orientation is the successful management of a relationship between suppliers and customers. During the past 15 years, a body of scholarship on antecedents and consequences of market orientation has emerged. But what is the appropriate level of market orientation, and what happens when customers and suppliers disagree about the appropriate level of a supplier's market orientation? To what extent does such disagreement concerning market orientation affect the customer-supplier relationship ? Do answers to these questions vary by country? The authors examine these issues using data from a survey of leading Japanese and U.S. business firms and their key customers that employed a unique matched supplier-customer sampling methodology. The authors report several interesting results.