This thesis examines the role of development banks in achieving sustainable development goals, with a special focus on the concept of green finance. In the first part, the fundamental principles of development banking are analysed, including its emergence, evolution, and functions. Besides that, there are diverse examples of development banks, highlighting globally significant development banks and the case of domestic – the Croatian Bank for Reconstruction and Development (CBRD). The second part addresses the core aspects of sustainable development. Historical context and definitions of sustainable development are taken into consideration, along with an investigation into the UNs Sustainable Development Goals (SDGs). Progress in achieving these goals is provided, enabling deeper insights into global efforts towards a more sustainable future. The pivotal section of the thesis concentrates on the contribution of development banks in attaining sustainable development objectives. Particular emphasis is placed on the concept of green finance as a crucial instrument for fostering ecological and societal initiatives. This section comprehensively analyses various types of green finance instruments and presents concrete examples, including green bonds issued by development banks like KfW. The study also encompasses examples of national development banks like CBRD.