This paper reviews the literature on inter-organizational information systems. It has long been argued that information technology can have profound effects on the structure and process of inter-firm relationships. This proposition has gained additional importance with the advent of internet, and resultant forms of business to business transactions over the web. Despite the interest and volume of research on this topic few theoretical generalizations have emerged. The lack of theorization has been compounded by the fact that the literature has grown in many directions to address various technological and practitioner concerns. To date, there have not been many reviews that put this body of work in perspective. To address this gap we propose a framework to review this field of research, and provide a means to reconcile the differences and appreciate the complementarities that run through this research stream. Our framework is based on two important themes, Inter-organizational information systems, and inter-organizational relationships. We argue that the research in this area can be effectively analyzed by understanding the persuasion of the researchers regarding these two central themes. The review is followed by a discussion of future research directions in this area.