This study deals with the issue of the Angelus prayer in the light of the documents of the International Marian-Mariological Congress, which was held in Lourdes on September 10-17, 1958. The theme of the congress held at that time was the relationship between Mary and the Church. The occasion for the celebration of this congress was the hundredth anniversary of Mary's apparitions in Lourdes. One of the topics that were taken up during the congress was the prayer “Angelus”, which has biblical roots and is spread throughout the Church. The article will discuss the history of the formation of the “Hail Mary” prayer, which is at the basis of the “Angelus” prayer. The study will also analyze the previously unpublished text by Father Carlo Balić, in which he asks John XXIII to issue a papal document on the prayer “Angelus Domini”.