In the 1960s, a generation of Latin American youth entered political life inspired by a heroic view of activism tiiat coincided, often contentiously, with the spread of new cultural trends from youth movements in Europe and the United States. This study focuses on how the notions of “being young” in circulation at the time affected the construction of political identities in Uruguay, particularly among the different branches of the Uruguayan left. I am especially interested in analyzing the relationship between the cultural representations of youth and the requirements for activism as conceived by these Uruguayan leftist groups.