The essay reconstructs some decisive stages in the history of JEC (Juventude Estudantil Católica) and JUC (Juventude Universitária Católica) in Brazil between the 1950s and 1960s, highlighting the influence of the francophone model of “specialized” Catholic Action on the history of the two Brazilian student movements. Since the second half of the 1950s, the Brazilian JEC and JUC had expressed a desire to move beyond an approach that focused exclusively on the religious education in favor of a model that combined both faith education and social action. This led the leaders of the JEC and JUC to look for models that they initially found in Maritain’s thought, as documented by the debate around the «Ideal Histórico» at the turn of the Fifties and Sixties, or in the theory of «Engajamento», which they took from the model of French Catholic Action. In just a few years, however, young Brazilians would come to a radical critique of the foundations of Maritain’s thought, from which they had started, outlining the theoretical and practical basis for the Theology of Liberation elaborated by Gutiérrez in the early 1970s. The events of the JEC and JUC, even with some peculiarities, represent a paradigmatic anticipation of some processes that will affect some of the Catholic Action youth groups in South America and Europe after 1968.