This research examined the ways politically active secondary teachers, involved either in formal politics or in social movements, practiced citizenship education in Porto Alegre, Brazil, and Toronto, Canada. The author's aim was to explore the complex ways and multiple spaces in which these teachers' roles as both citizens and citizenship educators intersected within the local contexts. His premise is that the local political and educational contexts are critical in shaping citizenship education practices. His approach is situated within a tradition of comparative education that emphasizes the role of culture in shaping schooling, which has typically focused on the historical origins of educational systems. He focused on the local political context in order to draw out the way that competing political beliefs drive approaches to citizenship education, which, in contrast to other subject areas, involves engagement with civic and political issues. Specifically, his research questions dealt with the extent and nature of the influence of teachers' political ideologies and participation on citizenship education practices and the ways that local political and educational contexts mediated this process. (Contains 2 tables and 21 footnotes.)