The article presents the methodological position of the French approach of the “économie des conventions” (economics of convention, in short: EC). EC is introduced as a new form of a pragmatist institutionalism, which assumes capable actors, a plurality of conventions and different forms of rationality. EC explains collective quality constructions and regards conventions as solutions for collectives to deal with uncertainty. EC criticizes mainstream economics because of its notion of rationality and its methodological individualism. The article focuses on the methodological standpoint of EC. It is argued that the influences from pragmatism and structuralism place this new institutionalism beyond pragmatism and structuralism and that its methodological position can be regarded as a “complex pragmatic situationalism”. The situation is the unit of analysis. In situations pluralities of conventions have an impact as possible logics of coordination and evaluation. The EC has a strong tradition in empirical historical analysis of institutional forms and socio-cognitive categories. It is argued that parallels to the Weberian methodology exist. But EC supposes that ideal types are common knowledge also to the ordinary actors. At the end it is the specific complex methodological position of EC that places it also beyond the opposition of methodological individualism and methodological holism.