Understanding the creation of value in business relationships has been a long-standing goal of researchers and managers alike. By adopting a relational perspective, recent research on business relationships has made much progress in understanding value-creating processes. As the sales function is thought to be a pivotal part of the value-creating processes in business relationships, the evolving view on creating relationship value clearly has implications for our understanding of the role of sales in these processes. In contrast to its importance, the question of how the sales function contributes to creating value in business relationships has been largely neglected in extant literature. The objective of our paper is to answer this question by systematically linking the relational value creating process to the sales function's content. Interpreting value creation as interaction process, we identify four features of value-creating processes in business relationships suggested in recent research (i.e., jointness, balanced initiative, interacted value, and socio-cognitive construction) and, based on these, outline a framework that is used to define a set of tasks that are key to creating value in business relationships and hence become critical for sales in its hitherto neglected role as co-creator of relationship value. We illustrate the various tasks of this new role of sales with data from 43 interviews with sales managers and salespeople. Along with related normative recommendations in extant literature, the interviews provide support for the validity and relevance of our framework for understanding the role of sales in creating relationship value. This framework puts forward a much-needed first effort towards a theory of sales' role in creating relationship value and offers several opportunities for future research