Leporinus obtusidens is a South American species of headstander that inhabits the basins of the Paraná River and the Río de la Plata, the Uruguay River, and the São Francisco River (including minor rivers and tributaries like the Bermejo, Pilcomayo, Salí, Juramento, Dulce, and Uniguay). It may be found in the main courses and streams, as well as in lakes and lagoons; it often shelters among stones and aquatic vegetation.