This article explains how Latin American governments responded to the Cuban revolution and how the “Cuban question” played out in the inter-American system in the first five years of Fidel Castro's regime, from 1959 to 1964, when the Organization of American States imposed sanctions against the island. Drawing on recently declassified sources from Argentina, Chile, Mexico, Uruguay, and the United States, the article complicates U.S.-centric accounts of the inter-American system. It also adds to our understanding of how the Cold War was perceived within the region. The article makes clear that U.S. policymakers were not the only ones who feared Castro's triumph, the prospect of greater Soviet intervention, and the Cuban missile crisis. By seeking to understand why local states opposed Castro's ascendance and what they wanted to do to counter his regime, the account here offers new insight into the Cuban revolution's international impact and allows us to evaluate U.S. influence in the region during key years of the Cold War.