Catholic organizations gather Catholics with the aim to consecrate the world though various apostolates. Laymen Christians ought to act in accordance with the Christian vocation by preaching about and participating in the establishment of the Kingdom of God. Historically, Catholic organizations appeared in Europe during the twentieth century, and they mostly started as workers’ associations, which later formed into various apostolate organizations. Organized work of Catholic organizations is called the Catholic movement. The work of Catholic organizations, as well as the Catholic movement, was also evident in Croatia, especially in the period between the two world wars. However, after World War II, the Communist regime did not allow them to act. Only at the beginning of the 1990s, with the establishment of democracy in Croatia, did Catholic organizations start to act once again. In the last thirty years, many Catholic organizations began to act within the Đakovo-Osijek (Arch)diocese. This master’s thesis presents the findings of the research conducted regarding the frequency of Holy Mass attendance and activities in the parish’s work, the definition of the aim of the organizations’ work and its accomplishment, the frequency and subject matter of meetings that are held, financing, membership number and performance autonomy, the satisfaction with the organizations’ work and ideas for its improvement, ways of participation in the work of the organizations, dedication of time and awareness of the social teaching of the Catholic Church. The aim of the organizations’ work is for their members to actively participate in spreading the mission of the Church and making the Gospel a source of hope for the revitalization of society and every individual. It is necessary for Catholic organizations to act under certain criteria so as to remain loyal to the authentic mission of the Church and to accomplish a mutually positive relationship for the development of the members, organizations and society. Membership formation includes spiritual formation and one that has a role in helping apostolate organizations. The results of the conducted research and the guidelines of the Church show correspondence in conveying the same values and needs for quality work of Catholic organizations.