AbstractOrganic agriculture distinguishes itself from other production systems by values that oppose certain mainstream agricultural practices. These values are in tune with policy instruments that attempt to change citizens' behaviour via communication, i.e. involving citizens' attitudes and social norms. Communication in support of organic agriculture takes place in the domains of agriculture policy, the farming community and the food market as well as within institutional settings that coordinate activities across domains. Available evidence from initial comparative studies in Europe suggest that the distinction between organic and mainstream agriculture institutions is weak within the farming community, but strong within agricultural policy. Public policies based on certification and financial support seem to have had limited impact on organic agriculture development. Finally, it seems that differences in organic agriculture development among European countries are positively related to institutional changes and continuing interrelations across domains and between organic and mainstream agricultural institutions.