This article examines the policies of Warsaw Pact countries toward Chile from 1964, when Eduardo Frei was elected Chilean president, until 1973, when Frei's successor, Salvador Allende, was removed in a military coup. The article traces the role of the Soviet Union and East European countries in the ensuing international campaign raised in support of Chile's left wing, most notably in support of the Chilean Communist Party leader Luis Corvalán. The account here adds to the existing historiography of this momentous ten-year period in Chile's history, one marked by two democratic presidential elections, the growing covert intervention of both Washington and Moscow in Chile's politics, mass strikes and popular unrest against Allende's government, a violent military coup, and intense political repression in the coup's aftermath. The article gives particular weight to the role of the East European countries in advancing the interests of the Soviet bloc in South America. By consulting a wide array of declassified documents in East European capitals and in Santiago, this article helps to explain why Soviet and East European leaders attached great importance to Chile and why they ultimately were unable to develop more comprehensive political, economic, and cultural relations with that South American country.