One of the most important sales operations that have spread among members of society today is the installment sale, and among the reasons for its spread are intense competition between producers and the weak purchasing power of consumers. More people need goods and have no money to buy them with cash, and many markets have suffered from the recession, so companies and institutions have devised new marketing methods to provide the advantages of goods that aim to acquire the largest possible number of consumers for these goods. This study aims to investigate the installment sale process and to review the potential of Islamic banks in developing financing products with the installment sale concept. The research method in this study uses a normative judicial method, aiming to concern one of the applications of installment sales in Islamic bank finance based on the existing law and regulation. This study concluded that the contemporary applications of installment sale concept in Islamic banks of Brunei Darussalam, in form of financing with Tawarruq contracts, Islamic hire purchase Ijarah Thumma al Bai’ (AITAB), and Musarakah Mutanaqisah (MMQ). With the concept of installment sale applied by Islamic bank-based Islamic law and regulation, so that we can all avoid doubts and become more confident in dealing with a transaction that is under sharia principles.