This article presents an analysis of the functional design of a collection of 346 projectile points from archaeological sites in the Puna de Atacama (21.9°–24.7° S) that belong to the cultural sequence dating from 12,500–2400 yr BP, which ranges from the earliest groups to inhabit the area to the emergence of the first agro-pastoralist societies. The results obtained reveal significant changes in projectile or weapons technologies throughout the sequence. This begins with projectile points whose measurements point to the predominance of the spearthrower-dart system during the Early Archaic, followed by the diversification and specialization of these technologies during the Middle Archaic, with a significant increase in the use of throwing and thrusting spears. In the Late Archaic, projectile point dimensions diminished significantly, displaying patterns that remained until the Early Formative. Nevertheless, during this last period some measurements decreased slightly, and a major change is detected in the haft width of stemmed points. Three alternate hypotheses are proposed for these last changes: 1) the presence of the bow-and-arrow system from the late Archaic onward; 2) the appearance of the bow-and-arrow system from the Early Formative only; 3) the reduction and standardization of spearthrower-darts, without the presence of the bow-and-arrow system until after the Early Formative. We argue that the first two hypotheses are the most plausible, although we consider the first to be the most likely.