Participatory action research has received increasing attention in geography in recent years, with numerous discussions about how best to proceed and lessons learned from past efforts. There has been less interest, though, in critically probing the circumstances under which participatory research takes place: in other words, the sociospatial contexts within which such research approaches are chosen. One explanation may be that participatory action researchers sometimes infer that the reasons for their choices are primarily ethical and political. In this paper, I consider this and other assumptions about participatory action research, drawing upon my own involvement in two action research projects in Ottawa, Canada. I argue that reflecting on this question is a particularly timely undertaking, given the 'actually existing neoliberalisms' in which professionalization and partnerships are becoming more prominent. I begin by reviewing what has been said about participatory action research and the circumstances under which this approach is likely to be selected, and reflect on how these discussions might be enhanced by linking their circumstances specifically to emerging analyses about spaces of neoliberalism. Using these insights, I then examine the sociospatial context for the two studies and how their characteristics had specific effects on their methodological choices. All of these elements provide the scaffolding for consideration of the rationalities that supported the usage of participatory research in one study and the lack of engagement with this approach in the other.