Seventeen genetic studies performed among the until recently hunter-gatherer Aché were reviewed and the corresponding data integrated to general information about this group, and to statistical tests of hypothesis concerning its origin(s). Two features of the Aché gene pool emerge: (a) the distinctiveness in relation to the general pattern of Amerindian genetic data; and (b) the reduced within population genetic variability. As for the origin of this people, the evidence suggests a general Tupian background with considerable introgression of Jê genetic material, which could be explained by the Tupi warfare habit of absorption instead of extermination of defeated individuals.