The dissertation examines in detail and systematically the features and peculiarities of the legal regulation and institutional system of municipal waste management. It reveals the diversity of approaches to waste and the peculiarities of the concept of municipal waste, examines the main features of the legal regulation of municipal waste in Lithuania and the European Union, discusses the stages of waste management and the responsibilities of the Member States in the field of municipal waste management. Through revealing the relationship with the basic principles of legal environmental protection, the dissertation examines the principles of municipal waste management law and their content. It analyses the institutional system of municipal waste management and the main problems in the application of legal regulation and service delivery models. It also reveals the concept of the circular economy, its relation to the principles of waste management law, the impact on the legal regulation of waste, the main directions of waste management and the functioning of the institutional system of municipal waste. The research provides answers to the questions of what makes municipal waste unique that such waste is subject to a specific regulatory regime, and why the implementation of the circular economy starts with the tightening of municipal waste management requirements. Does the transition to a circular economy require a review of the institutional model for municipal waste management and what regulatory changes are needed?