Increasing numbers of social movement scholars now advocate participatory and collaborative research approaches. These are often premised upon the assertion of a convergence between movement and researcher that implicates the latter in the struggles of the former. Naming this approach “solidarity research”, in this article I identify the components that provide the rationale for its pursuit. As well as affirming movement-researcher solidarity, this rationale also comprises a situated epistemology that asks academics to think reflexively about their research practice, the roles (...) they play, and the interests they serve. This reveals the diverging positionality, of knowledge and interests, that often exists between movements and academics. Such concerns give rise to specific methodological and ethical principles that indicate the importance of negotiating this positionality to successful collaboration. Reflecting on my own experiences trying and sometimes failing to conduct participatory research with transnational agrarian movements, I identify dynamics that enable and constrain the pursuit of such collaborative research within commitments to broader methodological and ethical principles of solidarity. (shrink)