This article reports a comparative analysis of the media’s political agenda setting capacity in 27 European media systems, aimed at testing the hypothesis that the magnitude of this phenomenon is moderated by factors such as development of the press markets, journalist professionalization, strength of public television or political pluralism. The empirical analysis relies on data collected by the expert survey European Media Systems Survey, the World Association of Newspapers, the European Audiovisual Observatory, and the research project Providing an Infrastructure for Research on Electoral Democracy in the European Union (PIREDEU). Results show that political agenda setting is perceived as more common in press markets in which newspapers work as means of horizontal communication (and are, as subsystem, politically imbalanced), but that journalist professionalization and strength of public broadcasting systems foster political agenda setting effects.