This chapter provides an overview and quantitative description of Brazilian strike activity between 1945 and 1989, which depicts more precisely what industrial conflict was like over these forty-five years. It examines the patterns of work stoppages in order to bring to light empirical evidence about some widely speculated questions on the nature of working-class political participation. The chapter explores the importance of political and organizational processes in the generation of industrial strikes. Generally speaking, the economic approach has viewed changes in strike activity as determined by the structure of the production process and fluctuations in the state of the economy. The chapter argues that the intensity, scale, and form of strike activity also are dependent on the availability of organizational resources capable of channeling workers’ grievances and of facilitating strike actions. It shows how workers developed alternative forms of organization and collective action in response to changes in power relations.