The aim of this work is to analyze deeper the reasons of the changes in the the administrative national health structure between 1943 and 1945. While the creation of the National Health and Social Action in 1943 responds to a long demand of academic circles, the administrative centralization and the unification of health and welfare functions (less than a year) expose considerations far from the administrative logic. This paper analyze the consideration that connect the complex relation between the national repatition with the provincial goverments and the charities organizations. Also we considered the injerence of the medical union in the definition of the heath politics and the Juan Domingo Peron ´s ascendancy from the Work and Social We...