We present obsidian compositional data obtained by X-ray fluorescence analysis in the Andean highlands (25-27°S/68-69°W) of northern Chile. Seventy-six samples (n = 76) from three lithic sources and six archaeological sites were analyzed, covering a chronological sequence from 10,100 to 500 cal BP. Compositional analyses indicate the exploitation of the Ciénaga Redonda and Cerro Manchado local sources as well as Ona-Las Cuevas and Salar del Hombre Muerto located between 200 and 230 km away on the eastern slope of the Andes, in northwestern Argentina. The results obtained show that the Puna de Copiapó has been a key area for circulation between the eastern and western slopes of the Andes since pre-Columbian times.