The objetive of this work is to reflect upon both the problemspresented when exercising comparison and the studies supported by its application. The text is part of a comparative research on workers education policies in three countries, Mexico, Brazil and Italy. Talking about methodological approach, we didn't start such reflection by the similarities, but by the diferences. The utilization of the historical method make possible to seek the differences among countries, starting from widerange historical processes (to understand history as a process), and to reconstruct them as part of a specific and complex reality, opened to transformations (to use history as a method). The discussion of comparative studies has several forms of analysis. In this work we seek to understand some questions that emerges from the comparison in anthropology, history, sociology and political science. Finally, we present one comparative methodological view on the theme of workers education policies.