Effective relationship marketing (RM) in a firm's global operations necessitates that the underlying aspect of reciprocity operate consistently across markets. Unfortunately, few studies have empirically examined the role of reciprocity in RM, let alone whether the effects of reciprocity in RM are universal across national cultures. To address these limitations, the authors examine reciprocity as a multidimensional norm whose dimensions of equivalence (what is exchanged) and immediacy (when the exchange occurs) influence relationship quality and satisfaction with performance in cross-border U.S.–Japanese interfirm relationships. The results indicate that the effects of reciprocity on relationship quality are conditional on national culture. Specifically, uncertainty avoidance positively moderates the positive effect of equivalence on relationship quality, while individualism and short-term orientation positively moderate the negative effect of immediacy on relationship quality. Moreover, a supplemental analysis indicates that the key mediating variable RM model may not hold across all cultures when predicting satisfaction with performance. These findings underscore the importance of adapting RM strategies across national cultures and provide managers with recommendations for developing high-quality cross-border buyer–seller relationships.