This degree work focuses on the recognition of nature as a subject of rights and its impact on the right to a healthy environment. Through different approaches and legal perspectives, the complexity of the socio-environmental reality is analyzed and the contribution of the Declaration of Nature as a subject of rights in the promotion of a healthy environment as a constitutional right is determined. The legal mechanisms that have granted this recognition are explored and its reception in society and in the legal field is discussed. In addition, the implications of the declaration of nature as a subject of rights in the protection of the environment and in the fight against climate change are examined.