This chapter starts by exploring the definition of ‘health information system’, what different elements constitute a health information system and how are these linked. Next, health information system governance is addressed by applying common principles of good governance to a health information system context. The following section focuses on national, subnational and international health information systems in Europe. What are the characteristics of health information systems at these various administrative levels? What are the differences and communalities between national health information systems in European countries? How do the main international organizations structure their health information systems? The chapter ends with an outlook on current and future developments that are likely to have a substantial influence on the way health information systems operate.