The Community Innovation Survey (CIS) is an important data source for studying innovation in enterprises and for producing innovation statistics for the enterprise sector. Introduced in 1992 as a joint initiative of the Organization for Economic Co-operation and Development, the Statistical Office of the European Commission, and a group of innovation researchers, CIS data significantly contributed to a better understanding of the drivers and results of innovation activities in enterprises. Today, the CIS is a mandatory survey in all European Union member states, and is used as a model for innovation surveys in many other countries, including the USA, China, Japan, and South Korea. In the chapter the conceptual foundations of the CIS are presented, as well as the content and the methodology of the survey. The potential of CIS data for various areas of innovation research is also demonstrated, but the criticism brought forward in terms of limited international comparability is also acknowledged. In the final part, the main challenges of the CIS are discussed, as well as how the survey may be further developed in order to better serve research needs. This includes more and better measures of innovation output, taking up new innovation concepts such as radical or disruptive innovation, and more quantitative data on innovation processes in enterprises.