The growth of business-to-business e-commerce has highlighted the role of computer and communications technologies as well as inter-organizational trust in developing and maintaining business-to-business relationships. Despite the acknowledged importance of trust, only a limited amount of research exists and that examines the role of trust in these relationships. By investigating inter-organizational relationships andtrust in e-commerce, this study will enable us to identify factors leading to successful e-commerce participation (adoption and integration). Drawing on theories such as trust in business relationships, inter-organizational relationship theories, transaction cost economics, and resource dependency theory, this paper develops a conceptual model to examine the impact of trading partner trust in e-commerce participation. The model is currently being tested through multiple in-depth case studies. The findings of the case studies are expected to increase the awareness of e-commerce adopters and implementers about the importance of trading partner trust in e-commerce participation.