This paper presents results of investigation of an early archaeological site in Uruguay, and considers its position on a regional scale. Pay Paso 1 is the first early site of Uruguay to yield both artifacts and faunal remains including records of Pleistocene fauna (Equus sp. and Glyptodon sp.) in a radiocarbon-dated stratigraphic context. From stratigraphic, chronological and archaeological observations, three cultural components for the Pleistocene-Holocene transition have been identified, together representing one of the most intensively AMS dated sites in South America. This solid chronological base allows the positioning of the peopling of Uruguay in the context of the early settlement of the surrounding region including northeastern Argentina and southern Brazil. The site is also remarkable because it yielded evidence of a blade technology at 12,802 cal yr BP, with numerous blades and a depleted blade core, which, together with the records from Laguna Canosa and K87 (Arroyo del Tigre), permit the definition of the Tigre and Pay Paso Paleoamerican cultural complexes. Tigre and Pay Paso bifacial points were produced in postFishtail times in the Low Plains, a vast open territory in Uruguay and southern Brazil.