Fiduciary security institutions are regulated in Law Number 42 of 1999 concerning Fiduciary Security (the Fiduciary Law). This law governs that any goods encumbered with fiduciary security must be registered in order to provide legal certainty to the interested parties. This fiduciary security registration provides the fiduciary receiver to acquire any priority right over any other creditor and to know the legal implication if fiduciary security deed is not registered to Fiduciary Registration Office. This research is a normative legal research which consists of 2 (two) types of legal materials, the primary legal materials consisting of various regulations and secondary legal materials consisting of books and information from the Internet in relation to the problems. In analyzing the result of the research, th writer used 2 (two) approaches, namely statutory approach and conceptual approach. The research concludes that fiduciary security deed must be registered to Fiduciary Registration Office to obtain a legal protection for the parties. If this requirement is not fulfilled, the creditor will not obtain protection rights as mentioned in the Fiduciary Law, such as the creditor can’t execute the fiduciary security. On the other hand, the legal protection that can also be given to the debtor is either preventive or repressive legal protection. Preventive legal protection can be given when debtor participats in the making of the agreement. In the repressive legal protection, the debtor may take action through litigation or non-litigation sector.