Recent studies on social movements have highlighted the importance of cultural and ideational factors. Concepts such as collective identity, cognitive praxis, and framing have been used to better understand the emergence, development, and political and cultural impact of social movements. In this article I draw on different schools of thought in order to develop a new use of the concept of cognitive practice. I suggest the relevance of analysing collective identities and cognitive practices at the organizational level (which does not, per se, exclude analysis at other levels). This emphasis also leads to a perspective that suggest a relational and interaction-oriented way in which to understand how movement organizations try to influence other actors through their cognitive practices. This kind of analysis helps to question the implicit notion of unity in the concept of social movement. The analytical focal points are also useful for discussing possibilities and dilemmas for movement organizations with regard to aspects such as how frames become effective and make frame resonance possible; how compromises and delimitations are built into frames; and how cognitive autonomy may be decreased or preserved. The empirical focus in this article is the Swedish environmental movement, and the identities and cognitive practices of some its organizations in the 1990s. I also discuss the relevance of my findings for the study of movement organizations within other fields