A year or two ago, on the occasion of a dinner meeting in Chicago in honor of some visiting colleagues from Latin-America, your speaker was impelled to discuss extemporaneously some of the important contributions of Latin-America to the advancement of radiology. When I was informed of the honor bestowed upon me by our Program Committee, I decided to enlarge upon this discussion by attempting to narrate the evolution of radiology in some of the countries of Latin-America. My special interest in this subject has been stimulated by visits of numerous radiologists from Latin-America to my work in Battle Creek, Michigan, and in Chicago, and by my own visits to Cuba and to Mexico, as well as by two tours of the principal coastal national universities of South America. Further help has been afforded by correspondence and by a search of available literature. Argentina When Roentgen's discovery was made known to the world, Dr. Jaime R. Costa, Professor of Medical Physics in the University of Buenos Aires, already established in his Sala de Fisioterapia in the Hospital Nacional de Clínicas, was able at once to utilize the new discovery, although the principal activity of the Institute concerned electrotherapy. Such progress was made in utilizing the x-rays that one of the early papers by Prof. Costa, “La practica de los rayos X,” published in Anales del círculo médico Argentina (23: 1, 1900) concerned their use in fractures and dislocations, localization of foreign bodies, detection of hepatic and renal calculi, aneurysms, determination of the position and size of the heart, height of pleural effusions, extent of pulmonary tuberculous lesions, size and mobility of the liver, and many other diagnostic uses. Professor Costa's Sala de Fisioterapia later became the Instituto de Fisioterapia, and still later the present important Instituto de Radiología y Fisioterapia Alfredo Lanari, which is under the direction of the present Professor of Radiology, Dr. Eduardo L. Lanari. A group of early workers in radiology included Alfredo Lanari, Humberto Carelli, and Carlos Heuser. Dr. Heuser in 1902 wrote an article entitled “Radiología” concerning which he said: “I designate this work with the title ‘Radiología’ because I believe it to be more appropriate and more restricted to the different branches of this phase of science: radioscopy, radiography, endoscopy and radiotherapy.” This was probably the first work published in the Argentine on radiology as a specialty. Heuser did notable work on the abdominal organs, kidneys, and pelvic organs, and between the years 1902 and the time of his death in 1934, he published a hundred or more articles on roentgen diagnosis and therapy and reported on various new methods of employing contrast materials for radiography. His diagnostic interests seemed to be focused on gynecological contrast studies. He made the first use of lipiodol in the genital apparatus in the year 1924.