The active implementation of climate change projects, the latest resource and nature-saving technologies, and environmental measures for the green growth of national economies require financial support. Currently, financial resources for environment-related investments and innovations are raised due to the increase of operational activities in banking institutions aimed at introducing green projects on the principles of environmental and socially responsible financing. This modern trend, known in the financial sphere as green banking, becomes relevant in countries where it is quite uncommon (for example, the Russian Federation and the Republic of Kazakhstan). The study aims at identifying the preferred tools for implementing the mechanism of green banking in Russia and Kazakhstan. The comparative analysis of expert opinions from Russia and Kazakhstan allows identifying both similarities and differences regarding the preferred instruments for providing monetary credits by green banking. However, the best lending rates for legal entities are considered the most preferable for experts from both countries. The authors of the article conclude that the creation of a segment of green products and services in the financial market will serve not only the implementation of the green economy principles but also the formation of an effective environmental policy as a mechanism for implementing sustainable development goals supported by environmental financial policy.