Anticommunism was a central force in the history of the Chilean political conflict in the 20th century. Not only did several political actors define their identities and actions by their opposition to Marxist-inspired revolutionary projects, but also the state in different moments excluded and persecuted everything identified as “communist.” To a great extent, anticommunism relied on three main “frameworks”: Catholicism, nationalism, and liberalism, all of which were crucial elements in the construction of the Republic since the 19th century. Different combinations and interpretations within each framework resulted in different anticommunist expressions, from pro-fascist movements and nationalist groups to the conservative-liberal right wing, the Social Christian center and even moderate socialists. Many of them, especially in the second half of the 20th century, understood anticommunism as a defense of different variations of capitalism. Of course, anticommunism was not a uniquely Chilean phenomenon. It was, in fact, an ideological trend worldwide. This conditioned the reception in Chile of global events and ideas, while it enabled the construction of transnational networks among related actors. The enactment of the Law of Permanent Defense of Democracy in 1948, which outlawed the Communist Party, symbolized the alignment of Chilean politics to Cold War bipolarity. However, the Marxist left was able to recover during the “long Sixties,” in a political and cultural environment marked by the Cuban Revolution. The Popular Unity government was the materialization of all anticommunist fears. The counter-revolutionary bloc created then paved the way to the 1973 coup and the subsequent military dictatorship, which used anticommunism as state ideology. Human rights violations were legitimated by the dictatorship from that ideological framework. Anticommunism decayed by the late 1980s alongside socialist experiences around the world.