Obsidian artifacts from Edzna, Dzibilnocac, and Santa Rosa Xtampak in northern Campeche, Mexico, have been analyzed by means of X-ray fluorescence in order to determine their trace element composition. The results are compared to the trace element composition of obsidian sources in Guatemala and Mexico. It is postulated that the obsidian from the three sites in northern Campeche came from highland Guatemala, mostly from El Chayal. Our data are compared to the published data of other archaeological sites in Mesoamerica from which obsidian samples have been analyzed. Finally, obsidian transport routes are postulated between northern Campeche, Mexico, and highland Guatemala.