The article is devoted to the study of national small and medium agribusinesses policy measures in the Eurasian Economic Union (EAEU) countries. To achieve the objectives of the study, the authors analyze the measures of state support for small and medium-sized businesses implemented in the EAEU member states as follows: the Russian Federation, the Republic of Belarus, the Republic of Armenia, the Republic of Kazakhstan, and the Republic of Kyrgyzstan. In the course of the study, the authors utilized the systemic and structural-functional methods of scientific development, the method of interpreting legal norms, as well as the logical method. Based on the results of the study, the authors concluded that it is necessary to consider the possibility of introducing new provisions into the EAEU Treaty, regarding the support of small and medium-sized businesses. A coordinated state policy to support small and medium-sized businesses on the territory of the single economic space of the EAEU could significantly affect the development of small and medium-sized businesses in the agricultural sector. In this regard, the proposed measures to support small and medium agribusiness are recognized as an incentive for the development of the agricultural market and the economy of the EAEU countries.