The article discusses some issues of the new decree of the Polish Bishops’ Conference regarding the canonical and pastoral investigations with fiancées before the conclusion of a canonical marriage. The decree passed on March 14, 2017 and still awaits for recognitio of the Apostolic See. The author focuses on the topics which are a novelty in the Polish particular church law on the preparation for marriage. These topics are as follows: common prayer of the pastor with the fiancées, the oath to be taken by the nupturients, the emphasis on conducting canonical investigation before the marriage with each fiancé separately and the obligation to keep the secret, deadlines required during the proceedings, parish jurisdiction with regard to conducting the canonical and pastoral investigations, the announcements, required documents, the need to obtain the consent of the local Ordinary of the place of the conclusion of marriage by persons residing abroad, natural obligations at the conclusion of marriage by persons who have previously had a relationship with another partner, the proceedings in the situation of an attempt to conclude marriage by persons after surgical and civil change of sex.