The primary orientation of the market economy is to create new value and ways in which credit and lending by banks and other credit institutions are both quicker nad easier. Banks are seeking certain security founds to secure the return of their loans. The legal instruments provided by banks in Croatian Law to secure their financial loans are pledge and transfer of ownership, as provided for in the Law on ownership and the other proprietary rights and Enforcement law. Mortgage on real estate as a kind of immovable property right is of particular immportance because of the nature of the property as a mortgage object, which is more valuable than movable property. This paper covers the concepts of the pledge rights and assesses the following areas ; the term real estate, the historical development of mortgages from Greece to Rome, the voluntary immovable property, the assumptions for its establishment, the mortgage agreement, the acquisition of pledged rights from non-owner, the transfer of mortgages,, and the powers and duties of different parties. The methods of settlement of mortgages are also explained through court (foreclosing) real estate sales, and other way of temporary administration and real estate valuation, which are not currently being implemented in practice. In conclusion, it is clear that mortgages are an extremly important asset when assesiing security instruments due to the durability and value of the real estate, and is acquired by entering into the land books, which because of the openness and availability make the mortgage the safest and the best insurance instrument.