Prior studies investigating business-to-business (B2B) e-commerce adoption have predominantly focused on institutional and transaction-cost theories while neglecting the influence of IT-based design characteristics on B2B e-commerce adoption. This study probes the design features of B2B exchanges, and their effects on perceived benefits, perceived costs, and intentions to adopt such exchanges. In this paper, we propose that the degree of website functionality provided by a B2B exchange positively influences the intentions of companies to adopt that exchange. Towards supporting this proposition, we identify a set of IT-mediated website services salient to B2B exchanges. We propose a theory that an aggregation of these services, what we refer to as website functionality, impacts potential B2B exchange users’ assessments of the costs and benefits of the services as well as their intentions to join the B2B exchange. This paper identifies website functionality in B2B exchanges and explicates the theoretical influences of such functionality.