
The article addresses the issue of an essential element of proving the invalidity of a marriage on the grounds of fraudulent misrepresentation (Canon 1098), which is the object of the deception. The basis for the analysis is all the decisions of the Metropolitan Tribunal of Cracow made between 2015 and 2020 on the above title. The paper outlines the title of nullity of marriage from can. 1098 and presents the importance that the subject of deceitful misrepresentation plays at the stage of instruction and judgment in the canonical process. The subjects of deceitfulness appearing in the presented jurisprudence form the essential part of this study. The author also proposes some legal and pastoral measures that may serve to eliminate the conclusion of invalid marriages. In conclusion, it should be stated that proving the object of deceit is an important aid for judges to achieve moral certainty about the nullity of a marriage on the title in question.