The objective of this research work was to determine the way in which the ex officio evidence provided by the Peruvian Constitutional Court contributes to the effectiveness of the amparo process in environmental matters. Due to the precarious regulation of the proof ex officio in the Constitutional Procedural Code, as well as the little doctrinal development of the subject, we have resorted to the general doctrine of ex officio proof and to the regulation that makes it the Civil Procedure Code to unravel the aspects that are applicable to the amparo process. Likewise, the jurisprudence of the Constitutional Court in environmental matters has contributed to highlight the particular characteristics of the fundamental right to the environment, as well as the influence of this in the configuration of the environmental protection process, which requires the establishment of special rules in i...