We contribute to the emerging literature on the role of socialization in developing buyer–supplier relationships. We conduct a dyadic, multiple-informant based, longitudinal study of the development of two buyer–supplier relationships. We carry out a detailed examination of the effect of socialization on communication quality by interviewing personnel from both the buying and supplying companies and at different levels over three consecutive years beginning with the inception of a key supplier program initiated by our focal buying company. Our results show that, contrary to what has been suggested by other studies, socialization in buyer–supplier relationships does not invariably have a positive impact on communication quality. We offer two possible explanations for our findings. First, we argue that the atmosphere created by past conflicts can diminish the positive effect of socialization on communication quality. Second, when a relationship is in a declining life-cycle phase, especially when one of the parties has strong doubts about the value of continued collaboration, socialization efforts may not contribute to improved communication performance. Hence, for socialization to have a positive effect on communication quality, socialization tactics must be tailored taking into account the history and current phase of the relationship.