This paper studies the criteria developed by the Chilean Constitutional Court over the last few years, to judge the legitimacy of the imposition of public burdens. The purpose of such study is to determine what is the autonomous and differentiated meaning of the notion of public burden, as well as its theoretical function in constitutional argumentation. To that effect, it starts by reviewing comparative and national scholarly discussion on the topic, in order to identify the key controversial issues. Then, it systematizes and analyzes the Court's case law, to elucidate what is the concept of public burdens it handles and what is the useful sense it gives to this idea.