Analysis of more than 3,000 lithic artifacts from the Cova Gran de Santa Linya site (Les Avellanes-Santa Linya, Lleida) shows that anatomically modern human communities occupying the southern Pyrenees during the Upper Paleolithic used flint (chert) exclusively for tool production. The findings, published in the journal Quaternary International, indicate that raw-material selection was closely linked to technological changes, mobility organization and the ways in which these groups interacted with the landscape.