In this article, we lay out the challenges and research opportunities associated with business-to-business (B2B) buying. These challenges and opportunities reflect four aspects of B2B buying that the Institute for the Study of Business Markets (ISBM: www.isbm.org) has identified through a Delphi-like process: (1) the changing landscape of B2B buying, (2) the increasing sophistication of sellers, (3) the impact of technological changes, and (4) the increasing importance and growth of emerging markets. For each of these four areas, we identify the relevant background, key issues, and pertinent research agendas.