During the year 2005, as part of the multidisciplinary project “Of the ethnic histories to the prehistory of the Gran Chaco”, two field trips to the wichi communities nearing the locations of Ingeniero Juárez and Laguna Yema (Formosa province, Argentina) were made. From the methodological proposal of a population unit, genetic data in 93 samples, employing binary markers and microsatellites of the Y-chromosome were obtained, determining male haplogroups and haplotypes. The Q1a3a haplogroup, native of the American continent, resulted the most common in both locations (72,7% and 81,6%). The molecular lineages were compared with the registered surname diversity and the possible links between the wichi communities were analyzed through “median joining” networks, finding a lineage variability that is reasonable given the distribution of the partialities of the “wichi ethnic complex” proposed by Braunstein.