If creditor lent money to debtor, then debtor has to pay off his debt to creditor. In order to convince the creditor, debtor usually provides certain collateral. The collateral is also useful as the payment of debtor’s bill in case he breaches the agreement. Creditor that’s holding collateral rights is called separated creditor. Mortgage and Fiduciary Security are examples from many kinds of collateral rights. They give the rights to the holder for selling the object from the collateral rights. In facts there are many separated creditor that filling the petition for declaration of bankruptcy to Commercial Court, instead of selling the object from the collateral rights straight away. Based on that problem, the author intends to research about the legal standing of separated creditor in regard of filling the petition for declaration of bankruptcy. This Thesis uses normative legal research with 2 (two) approaches, which is statute approach and case approach. For statute approach, author uses Law Number 37 Year 2004 on Bankruptcy and Suspension of Obligation for Payment of Debts. For case approach, author uses case of PT. Bank Internasional Indonesia, Tbk against Tn. Jung Dianto and Ny. Lily Eriani. PT. Bank Internasional Indonesia, Tbk as separated creditor can fill the petition for declaration of bankruptcy according to elucidation of Article 2 paragraph (3) Law Number 37 Year 2004 on Bankruptcy and Suspension of Obligation for Payment of Debts.