Shortly before the Mexico Olympics, on 2 October 1968, student demonstrators were shot by the military on Tlatelolco Square in Mexico City, thus ending the local student movement and its mass protests. This paper explores the government's use of anti‐communism to ideologically justify this massacre in the context of the Cold War. The student movement was presented as a foreign, communist intervention that threatened Mexico's sovereignty. The paper analyses the weaknesses and contradictions of this official narrative by contrasting public and confidential reports. Finally, the marginal role of communism in the movement and its internal divisions are also outlined.