The article shows the relations between the Holy See, as the supreme authority of the Catholic Church, and the communist states in Europe. Article consists of two parts. The first part shows the standpoint of the Holy See against the communist regime in the Soviet Union from the October Revolution to the end of the Second World War. Then The Holy See undertook a dialogue with the representatives of the communist authorities in order to provide charitable assistance to the starving population and to gain the opportunity to conduct pastoral activities among the faithful. In the first phase the communist authorities proposed the Holy Seen to sign an international agreement and to establish diplomatic relations, but the communist authorities did not want to end the fight against religion and persecute the Church. In the second phase, all contacts between the Soviet Union and the Apostolic See were broken. Then Pope Pius XI made a critical assessment of the ideological assumptions and methods of exercising power by the communists (enc. Divini Redemptoris). The second part shows the relationship between the Holy See and the communist states of Central and Eastern Europe, which after the Second World War the communist regime were imposed and the Soviet Union – from the end of the Second World War to the break-up of the communist bloc in Europe. After Second World War, the authorities of these countries broke off their diplomatic relations with the Holy See and the concordat agreements of the interwar period and adopted a policy of limiting Church freedom and discrimination against believers. In this situation, the Holy See has granted the diocesan bishops in these States the special privileges (facultates speciales) for the purpose of ensuring that the Church functions are as in normal circumstances. During the pontificate of the Pope John XXIII a dialogue was initiated between the Holy See and the authorities of the communist states in order to secure peace and respect for human rights and religious freedom. On the other hand, the authorities were keen to obtain support from the Holy See on their international policy, but they did not stop the restriction of religious freedom. Radical changes took place only during the pontificate of John Paul II.