The work of Dr. Claudio Costa Casaretto covers a broad field in the history of Medicine in Chile. He contributed with the historical aspects in the Centennial issue of Revista Médica de Chile in July, 1972. He published 85 papers in this journal in a lapse of 20 years. In his works, he investigated about medical personalities with the highest relevance for Chilean medicine such as Dr. William Blest, graduated in Edinburgh and director of the first Medicine Course in Chile in 1833, the French obstetrician Dr. Lorenzo Sazie, first Dean of the Faculty of Medicine of the University of Chile in 1843 and Dr. Eloisa Díaz, first physician graduated in Chile and South America in 1887. He published the translation from Latin of Juan Ignacio Molina s verses "Elegies to smallpox", Chilean writer and erudite of the XVIII century. He also undertook the origins of Universidad de San Felipe (1737), Universidad de Chile (1842) and Pontificia Universidad Católica de Chile (1889) and the main educational events occurred in the Faculty of Medicine of the University of Chile, during the past century. He also published about the public health situation and sanitary care during the XIX century, about the conflict between private and public teaching and other political events of the past century. The work of Dr. Costa as a whole, is a real history textbook of Chilean Medicine. Dr. Costa and Dr. Enrique Laval are the most important Chilean medical historians of the XX century.