The subject of this work is the institute of fiduciary, developed in Roman law, but because of its importance it is now being applied in many legal systems around the world. Despite the lack of resources and the omission from Justinian's codification, this institute resisted oblivion. Analyzing the genesis of this institute, there is a need for better securing the creditor's claim, as well as protecting the debtor, which fiduciary allows. Numerous countries, including the Republic of Croatia, took over this Roman law institute with certain modifications, so fiduciary today is known to be the prototype of Roman fiducia cum creditore. By concluding, business practice needs the institutes that will be the best for creditors, but on the other hand, it can be extremely risky for debtors. The legislator's task is to provide protection to the debtor and to precisely regulate the relationship between the contracting parties. In the Croatian legal system fiduciary was introduced by the Enforcement Act through judicial and public notary insurance by transferring ownership of property and transfer of rights. The aim of this paper is to present the historical development of the institute of fiduciary, its advantages and disadvantages, a comparative view, and to show today's application of this institute and legal regulation in the Republic of Croatia.