This chapter explores the evolution and legal intricacies of environmental constitutionalism in Brazil. Environmental protection is enshrined as a fundamental right, immune to constitutional amendments. Article 225 of de 1988 Constitution articulates collective duties to preserve an ecologically balanced environment, imposing obligations on both government and individuals, including criminal and administrative penalties for violations. Indigenous rights are pivotal, with Arts. 231 and 232 recognizing their stewardship over traditionally occupied lands. Yet, legal disputes persist, highlighting the precarious state of Indigenous territories. Environmental assets are classified as public goods for communal use, transcending traditional notions of ownership. This classification confronts collective action challenges, necessitating robust legal frameworks to prevent overexploitation. Principles of sustainability guide property rights, ensuring environmental preservation and justifying claims for ecological damages. The narrative, steeped in historical evolution, constitutional debates, and socio-legal complexities, portrays Brazil’s environmental constitutionalism as a progressive but contested landscape, intricately balancing rights, duties, and preservation against economic and political pressures.