This paper presents a review of the challenges of international scholarly scientific collaboration. It looks at institutional constraints and points out that the challenges and problems multiply when collaborators come from different countries with differing conditions, resource endowments and institutional structures. It is easier to call for more and better forms of international collaboration than it is to design them. The report asserts that good design is helped by a better understanding of what collaboration is and how it has been carried out. It draws on social research insights to help reduce the transactional, financial, ethical and emotional costs of international linkages and exchange and provides a conceptual framework for thinking about international collaboration issues.