This article is a contribution to the debate on audience participation in online media with a twofold aim: (1) making conceptual sense of the phenomenon of participatory journalism in the framework of journalism research, and (2) determining the forms that it is taking in eight European countries and the United States. First, participatory journalism is considered in the context of the historical evolution of public communication. A methodological strategy for systematically analysing citizen participation opportunities in the media is then proposed and applied. A sample of 16 online newspapers offers preliminary data that suggest news organisations are interpreting online user participation mainly as an opportunity for their readers to debate current events, while other stages of the news production process are closed to citizen involvement or controlled by professional journalists when participation is allowed. However, different strategies exist among the studied sample, and contextual factors should be considered in further research.