This paper compares the role innovation plays in productivity across four European countries, France, Germany, Spain, and the UK, using firm-level data from the internationally harmonized Community Innovation Surveys (CIS3). Despite a considerable number of national firm-level studies analysing this relationship, cross-country comparisons using micro data are still rare. We apply a structural model that describes the link between R&D expenditure, innovation output, and productivity (CDM model). Our econometric results suggest that overall the systems driving innovation and productivity are remarkably similar across these four countries, although we also find interesting differences, particularly in the variation in productivity that is associated with more or less innovative activities. © 2006 Oxford University Press.