This article explores, through a comparative analysis of cultural practices and discourses, part of the literary and militant activities of Rodolfo Walsh, in relation to some of the most significant aspects in the shared emergence between Latin American testimonio and Third Cinema. For that purpose, the text investigates the role played by Cuban revolutionary institutions and publications (Casa de las Américas and ICAIC; and magazines Casa de las Américas, Cine Cubano and Tricontinental) in legitimizing and disseminating these proposals in literature and cinema. This cultural policy was part of a very particular type of confluence between culture and politics, which was inscribed within a Latin American and Third World revolutionary project. The Cuban position problematized the question of the revolutionary potential of the arts among writers, intellectuals and artists, something that would reach a critical moment with the perception of the exhaustion of certain forms of expression and the tragic death of Che Guevara in 1967. Ultimately, this context led to strong controversies and radical proposals that would give rise to the appearance of testimonio and Third Cinema. Walsh, in different degrees, went through this experience, materializing both in his work and in his militancy, the particularities of an entire cultural era ?a time of such significance for Latin America and the Third World that it would end up impacting the First World as well.