The purpose of this work is the study of degeneration theory in Chile within the original context of its appropriation. Degeneration theory has been the object of attention in Chilean historiography as essential to the study of alcoholism, asylums and mentalities at the end of the nineteenth and at the beginning of the twentieth century amongst other themes. This has resulted in a relative ignorance of both, the original context in which degeneration theory was created in French psychiatric hospitals during the second half of the nineteenth century, as well as its initial appropriation in Chile for the treatment of psychiatric illnesses. Consequently, this investigation has been carried out using public medical discourses: academic articles, memoirs and expert opinion. This work shows the evolution and peculiarities of the process of appropriation of degeneration theory in Chile and provides a few perspectives about its continuity in Eugenic discourse during the twentieth century.