A guarantee is an assumption of a debt or a promise by someone to assume the debt if the debtor fails to fulfill it. Third parties can be guarantors or owners of collateral that is not included in the debt. Debtors can file for bankruptcy if they experience financial difficulties. Often, a debtor enters into a credit agreement with a creditor, and not only pledges assets in his or her own name, but also includes the assets of a third party as collateral for the credit agreement. However, there is a problem when the collateral assets belonging to the secured third party are included in the list of bankruptcy assets. This can be seen with the creation of dualism in court decisions stating that collateral assets belonging to third parties are included as bankruptcy assets of bankrupt debtors and some state that they are not included as bankruptcy assets. This condition can interfere with legal certainty in the community. there are 3 problems in the research, namely How are the Regulations Regarding the Position of Third Party-Owned Collateral Assets in the Management and Administration of Bankruptcy Assets in Indonesia? How is the Implementation of Regulations Regarding Third Party-Owned Collateral Assets in the Management and Disposition of Bankruptcy Assets in Indonesia? How is the Legal Certainty of Third-Party Collateral Assets in Bankruptcy in Indonesia? This research uses normative-empirical research with a statutory and conceptual approach. Regulations regarding the position of collateral assets belonging to third parties in the management and administration of bankruptcy assets in Indonesia are contained in Article 21 of Law 37/2004 as well as a guarantee agreement as an accesoir agreement. Then, the application of arrangements regarding collateral assets belonging to third parties in the management and administration of bankruptcy assets in Indonesia currently has dualism. Thus, legal changes can be made to Article 21 of Law 37/2004, by changing the provision that bankruptcy property is the property of the bankrupt debtor and adding a provision that collateral assets belonging to third parties are not included in bankruptcy property as an affirmation of the previous provision.