Concurring with the view that political opportunity structures and citizenship regimes affect participatory patterns of immigrants through shaping associational activity and mobilization of immigrant groups, this essay examines the evidence from the case of Turkish immigrant associations in Canada to delineate and analyze variables other than institutional context and citizenship regimes that constrain collective participation. It focuses on the impact of history of immigration by Turks to Canada (Montreal and Toronto), trajectory and scope of associational activity, group size and heterogeneity, and political participation. It concludes that collective mobilization and participation by immigrant groups are constrained by intra-group characteristics alongside the institutional context of the receiving country.