This article describes the attitudes and policies of Salvador Allende towards Bolivia, from his days as a congressman until the end of his administration. We posit that during his presidency Chile developed a strategy that mixed pragmatism and ideology, trying to reestablish diplomatic relations with La Paz in exchange for an open discussion on the Bolivian aspiration an access to the sea. Allende took advantage of the ideological affinity with the government of Juan José Torres to generate trust between the two governments. However, this strategy backfired when a hostile ideological government took power in La Paz, which led, once again, to a deterioration of relations.