Genetic variation is generally responsible for ethnic differences in certain diseases, including inflammatory processes. The antagonist of cytokine IL-1, IL-1Ra, has been widely studied among Caucasian and African populations for genetic polymorphisms, and interethnic differences have been documented.However, the variation and genotype distribution of polymorphisms from these genes among South American Amerindians are thus far unknown. We present the results for a VNTR located in the IL-1Ra second intron, in a sample of 169 individuals belonging to 5 Native American populations from Argentina and Paraguay, identified as native according to their self designation, and their geographic location. We also compare this data with the results obtained from a sample of non-native Argentinian people. (Párrafo extraído a modo de resumen)