The results of source analysis by EDXRF of obsidian artifacts from the Mesoamerican site of Cerro Palenque in Honduras are reported and changes over time discussed. Sources of obsidian include Ixtepeque, El Chayal, Jalapa, San Martin Jilotepeque, and San Barolome in Guatemala. Some Pachuca obsidian from Mexico was also found. Honduran sources include La Esperanza and La Union. The implications of the obsidian sources are discussed in the context of changes at Cerro Palenque over time as it becomes the largest settlement in the lower Ulua Valley (Sula Valley) in the ninth century AD