Los Naranjos is one of the most important pre-Columbian human settlements of Honduras related to the south-easternmost border of the Mayan civilization. Although the archaeological site mostly spans from 850 BC to 1250 AD, the present obsidian study was only focused on the Preclassic and Early Classic periods (Jaral, 800-400 BC and Edén, 400 BC-550 AD) where undamaged blades and/or retouched obsidian flakes are rare. In this way, the INAA analyses of 17 obsidian samples, compared with major-trace elements data of Honduran and Guatemalan obsidian sources, are mostly representative of waste flakes. Lithic artifacts of Los Naranjos such as sandstones, basalts, and quartzites come from local geological outcrops; whereas, obsidian provenance has to be searched from sources which are located within a radius up to 300 km far away. San Luis, La Esperanza, and Güinope obsidian sources are located in Honduras while the three most exploited Highland Guatemalan obsidian outcrops, which have been dominating long-distance trade in the Maya area mostly for the Classic-Postclassic periods, are San Martin de Jilotepeque, El Chayal, and Ixtepeque. An Ixtepeque provenance, for all the investigated obsidian samples of Preclassic and Early Classic periods found in the Los Naranjos Archaeological Park, was established, thus emphasizing a long-distance source (180 km). This also confirms that Ixtepeque represents the most important provenance of the obsidian artifacts found in archaeological sites of Western and Central-Western Honduras. The possible role played by some of the most important rivers of Guatemala and Honduras as waterway networks of transport was finally pointed out. New INAA chemical data from the Honduran obsidian source of La Esperanza ('Los Hoyos', 4 samples) are also reported in this paper. [ABSTRACT FROM AUTHOR]