This article objective to investigate the medical conceptions about alcoholism and yours social repercussions from the experience of Lima Barreto as a patient in the Hospital Nacional de Alienados (HNA) from Rio de Janeiro, between the years 1919 to 1920. The author writhed about alcoholism, madness and scientific theories at the beginning of the twenty century. Writhed about the social differences and the relations of power in the asylum. The thinking medical eugenics defined the alcoholism according to the principles of degeneration and heredity. The writing of the author worked as a self production that questions the principles eugenics determined that the medical practices of confinement and cure.