The aim of this historical review is to evaluate the evolution of genetics in the context of Latin American scientific culture, to value foreign influences and to highlight the discoveries and contributions of Latin American geneticists. During the first third of the twentieth century, local naturalists, botanists and physicians understood the chromosomal theory of heredity and Mendelian theory of evolution and begun research and teaching on these new theories and technologies. During the thirties and forties, North American geneticists visited South America and formed development poles on cytogenetics and population genetics in Brazil and Argentina. During the fifties and sixties, human genetics was formally established in Brazil, Argentina and Chile. Genetics teaching became generalized in universities and national Genetics Societies were formed. In 1969, the Latin American Genetics Society was created, unifying the efforts of zoologists, botanists, physicians and anthropologists in an unique Latin American cultural space, organizing 11 meetings between 1972 and 1994. Latin Americans have made a great contribution in genome discovery of animal, vegetable and human species in their territory. They explored the great genetic diversity of the continent, discovering new genes and diseases. The biomedical area had the greatest development. In 1997, there were 130 medical genetics centers, 120 hospitals specialized in congenital malformations, 56 molecular biology centers and 26 molecular genetics centers. At the end of the twentieth century, human genetics is completely integrated to medical sciences in Latin America.