This article explores the Holy See's policy during the Second Vatican Council and the post-council period, called Ostpolitik, toward the socialist, non-aligned country of Yugoslavia. It puts the relations between the Holy See and Tito's Yugoslavia into the broader context of East-West rapprochement and analyzes the reasons both sides had to reopen dialog. The reestablishment of diplomatic relations–‒ which had ceased in 1952 — was of high importance to both. Yugoslavia saw relations with the Holy See as pivotal to its rapprochement with the West, while the Holy See wanted to use Yugoslavia as an example for its relations with other socialist countries. The milestones in the development of the relations between the Holy See and Yugoslavia, such as the signing of the Protocol of 1966, the establishment of full diplomatic relations in 1970 and President Tito's official visit to the Vatican in 1971 are analyzed. The influence of the relations with Yugoslavia on the Holy See's policy toward decolonized countries and the Non-Aligned Movement, as well as its attitude toward internal tensions in Yugoslavia (e.g. the Croatian Spring) are also examined.