The evolution of the law caused the emergence of principles of interpretation that can apply to several formal sources. Thus, principles of interpretation have been developed related to the law and the Constitution. The modern trend towards the materialization of the law raises the question of the principles of interpretation of the fundamental rights. This type of interpretation of the fundamental rights would point out a paradigm shift, towards a material justice. This paper seeks to analyze the way the case law —mainly the Chilean case-law— is incorporating some of these principles of interpretation of the fundamental rights.