In addition to the change in understanding in the provision of services and marketing, banks provide their customers with different experiences through ever-improved and diversified products and services. Especially in recent years, it is observed that banks have reached a wider customer portfolio by working as agents of insurance companies, mediating bancassurance transactions, and through partnership agreements with various insurance companies. This dynamic process also has a positive effect on financial performance since it causes banks to respond swiftly to the expectations and requests of their customers and increases the level of satisfaction. When considered from another point of view, however, this dynamic behavior can also increase the risks that banks are exposed to, leading to financial failures. Therefore, the financial performance of banks is often evaluated in the literature and the factors affecting financial performance are determined. However, in the literature review, there was no study measuring the reflections of insurance business partnerships on bank performance. Yet, banks that have a partnership with an insurance company will be able to contribute to their own performance by taking a share of both the insurance transactions made and the financial performance of the insurance company. Therefore, it is a likely expectation that the banks having a partnership relationship with an insurance company will be ahead of other banks in terms of financial performance. Thus, the main research topic of this study is the determination of the effect of the provision of insurance products by an insurance institution, acting as a joint venture of the bank, on the financial performance of the bank, using ENTROPY and TOPSIS methods, which are multi-criteria decision making methods. For this purpose, financial performances of 8 banks (4 large-scale, 4 medium-scale), selected among the banks with or without a partnership with any insurance company, were measured using financial ratios, consisting of 7 main criteria and 35 sub-criteria, between 2011 and 2020. According to the results obtained, the existence of a partnership relationship with an insurance company, especially in large-scale banks, positively affects their financial performance.