Today, environmental protection is a priority task for the governments of countries around the world due to the deepening of environmental problems and their impact on people's lives. Several problematic issues can and must be solved at the local level, which will make environmental policy more effective and take into account local needs. The study aimed to analyse the competence of local self-government bodies in terms of monitoring compliance with environmental legislation. A comparative analysis was used to study the issue of ensuring the protection of the environment and ecosystem by local self-government bodies through the prism of legal protection. During the research, several obstacles to the implementation of effective environmental protection measures at the local level were identified: the imperfection of the financing system, the lack of environmental awareness, the absence of effective administrative and procedural measures, and the imperfection of state control. In response to the identified problems, the positive experience of implementing the norms of the European Charter of Local Self-Government was investigated. It was established that the decentralization of local self-government had a positive effect on the protection of the ecosystem, as it brought local authorities closer to the public and provided local authorities with real powers to solve problems related to compliance with environmental legislation. In addition, to increase the effectiveness of mechanisms of state control over local self-government in the field of environmental protection, a system of principles of such control is proposed, consisting of publicity, systematicity, effectiveness, objectivity, impartiality, and universality. The proposed system will cover several key environmental problems and quickly and effectively solve them with the involvement of competent specialists and the public. The state of environmental protection at the local level is seen in further research and justification to determine practical recommendations for the implementation of decentralization of local self-government.