Notwithstanding the growing literature on international buyer-seller relationships, limited attention has been given to the crucial role of adaptation in enhancing relationship performance, especially from the standpoint of the importer. This article reports the findings of a study, conducted among 167 British importers, focusing on the factors that drive their adaptation in the working relationship with Western European or U.S. export manufacturers, as well as its resulting performance outcomes. It was revealed that trust positively affects commitment and cooperation, while communication positively influences cooperation but has no effect on commitment. Both commitment and cooperation subsequently lead to importer adaptation. It was also found that adaptive importers tend to be more conducive to effective and efficient relationship outcomes. Finally, the study confirmed that both the links between adaptation and relationship effectiveness and adaptation and relationship efficiency are moderated by both the level of dependence on and distance from the exporter. © 2010 Elsevier Inc.