Inter-organizational Interaction in Public and Private Sectors -A Comparative Study 1Purpose -This article compares inter-organizational (IO) interaction and inter-organizational information systems (IOS) to support IO interaction in public and private sectors. The purpose of the article is to explore and discuss differences and similarities between e-government and e-business focusing IOS and interaction. This is done in order to facilitate learning between the two fields. The point of departure is two case studies performed in private and public sectors.Design/Methodology/Approach -A comparative study of two cases in two sectors (private and public) is conducted. IO concepts from industrial markets that characterize an IO relationship (continuity, complexity, symmetry, and formality) and concepts that describe dimensions of such relationships (links, bonds, and ties) are used as analytical lenses. The empirical case study data, mainly generated from interviews, has been analyzed in a qualitative, interpretive way, using these central IO concepts from industrial markets (The IMP approach). This approach is in line with a strategy to use theory as a part of an iterative process of data collection and analysis.Findings -The findings in the present study show that there are several similarities concerning interaction in relations between organizations in the two sectors. There are also differences depending on the level of analysis (empirical level vs. analytical level). The study shows the need to be explicit regarding organizational value, endcustomer or client/citizen value and the type of objects that are exchanged in the interaction. This is presented in the article together with suggested refinements of the analytical framework used for understanding IO interaction. The latter finding is a contribution to the general field of interaction and network studies and also a contribution to the e-government field.Research limitations/implications -This research provides understanding of similarities and differences in the two sectors when analyzing IO interaction and IOS. The study also illustrates a systematic way of analyzing and comparing IO interaction and IOS use in different sectors. However, it is also urgent to learn more about IO interaction between a private and a public organization and how it would be beneficial for understanding both sectors. The issue of trust is an important aspect that is embedded in the IMP approach used in this article. Further understanding of IO interaction can be reached by applying research focused on trust as such. Thus, the findings call for more studies in the area of inter-sector learning, IO interaction and e.g. trust.Practical implications -This article is a point of departure to facilitate learning between the public and the private sectors focusing on IO relations and IOS. Learning between the two sectors is needed for researchers in the two areas as well as policy makers and practitioners developing e.g. e-government interaction and IOS.Originality/value -There are fe...