The subject of this paper is to get acquainted with the legal institute of immovable property rights for which the mortgage name is frequently used. It is an institute of real rights, which represents the realistic securing of the creditor's claim, and serves to strengthen the creditor's position. Mortgages, as a type of real rights of limited content, are regulated in the positive legislation of the Republic of Croatia by the Law on Ownership and Other Real Rights, the Enforcement Act and the Land Registration Law. In addition to getting acquainted with certain articles of the aforementioned laws, the paper uses a number of professional literature and scientific journals to gain a better insight into this legal institute. The basic features of the pledge rights are generally described, the elementary features and the foundation of the mortgage are defined, each separately explains types of the mortgages and the authority of the mortgage lender, with particular emphasis on the foreclosure that comes to the settlement stage. Since this is a very complex and extensive subject, there is certainly a lot left unprocessed but the theses with certainty provides a good insight into the fundamental features of this legal institute.