Over the last decade, the free software for automatic delimitation of hydrographic basins has been showing significant improvements in results. This study had as objective the automatic delimitation of the Itapemirim River Basin (BHRI) using different free software. The acquisition of the data used in the processing was possible thanks to the Topodata project, which provided data on Digital Elevation Modeling (DEMs) and its derivations provided by Instituto Nacional de Pesquisa Espacias (INPE, 2011) at a scale of 1: 250,000 for all national territory, these data were integrated and processed in a Geographic Information Systems (SIG) environment. The software used in the preprocessing was the QGIS, and for the processing were used the software Mapwindow and Terrahidro. The procedures performed consisted on the following steps: 1) flow direction, 2) flow acumulation, 3) drainage extraction, 4) Segments and vector segments, 5) watersehd delineation. It was possible to prove that the results obtained when automatically delimitating hydrographic basins in free software can be considered satisfactory for the areas in which a high slope index is presented, but in flat areas, only the Taudem processing returned excellent results, thanks to its better execution in the process of extraction of drainage in flat áreas.