The decision to get married changes the life of the engaged couple. For this reason, good preparation for this sacrament plays a very important role. The direct stage of preparation for marriage is associated with participation in premarital classes and a visit to the Family and Pastoral Counseling Center. The analysis of the spatial distribution of the parishes of the Katowice Archdiocese, where preparation for marriage takes place, was possible thanks to an interactive map on the website of the Family Pastoral Care Concern of the Katowice Archdiocese. The map and analysis was made thanks to the Geographic Information Systems (GIS ) tools. This article also examines whether the location of the forms of preparation for marriage is related to the population density and the age structure of population in Katowice Archdiocese. Thanks to this, it was proved that it is possible and beneficial to combine the subject of theological research and family sciences with geographical research tools.