Participatory Action Research (PAR) aims to articulate knowledge production and transformative action. In this paper, we outline the sociopolitical background to our interest in LGBT and trans-collectives as an important territory where PAR might make some intervention in the social conditions of LGBT lives by transforming dominant forms of representation that have emerged from a history of psychological and medical pathology. We present two projects, from UK and Spain that utilize post-structuralist informed methods (interviews, photo-production, discourse analysis, narrative production) within a PAR framework. We examine their potential for problematising representations of sexuality and gender by reflecting on the knowledge produced and the transformative action they provoke. We rethink power relationships inherent in PAR concepts of ‘participation’ and ‘empowerment’ through a post-structuralist lens and argue that the achievements of PAR projects can be better understood as ‘co-produced artifacts’. These (e.g. photo-exhibition) are co-owned by community members and researchers and their deployment in different settings (e.g. community or university) impacts on the meanings they convey and the action they provoke. Finally, we argue that through the use of post-structuralist methods PAR can enable effective transformative action, but caution against the practice of reinstating normative representations in the invitation to participate under specific identity categories (e.g. LGBT, Trans, mental health service user). PAR projects can do this by considering naturalized definitions of who is vulnerable or marginalized as the object and field of social transformation, and the starting point for collective and political action. Copyright © 2012 John Wiley & Sons, Ltd.