The Catholic Church, as one of the longest-standing institutions with an uninterrupted existence in the history of the Croatian nation, has become the leading religious community in the Republic of Croatia due to its concern for the preservation of the national and cultural identity of the Croatian people and the very fact that the majority of the population of the Republic of Croatia belongs to that community. The Republic of Croatia has signed and ratified four agreements with the Holy See that regulate the legal framework of activities and the position of the Catholic Church in the Republic of Croatia. These are the following contracts: 1. Agreement on Legal Matters, entered into force on April 9, 1997 2. Agreement on economic matters, entered into force on December 14, 1998 3. Agreement on pastoral care of Catholic believers, members of the armed forces and police services of the Republic of Croatia, entered into force on April 9, 1997 4. Agreement on cooperation in the field of education and culture, entered into force on April 9, 1997 Since the entry into force of the aforementioned agreements, their validity, their implementation and Constitutional compliance have been discussed, which will be presented in this paper. Also, the results of a survey conducted on 147 respondents are presented, and regarding their knowledge and attitudes about the relationship between the Republic of Croatia and the Catholic Church.