The chipped stone industry of Cihuatan and Santa Maria, Postclassic sites of north-central El Salvador, is discussed briefly in terms of behavioral/technological typology. The industry was based almost exclusively on obsidian and emphasized specialized production of prismatic blades. Source determinations by X-ray fluorescence and neutron activation analysis of 20 obsidian specimens from Cihuatan indicate that at least three highland Guatemalan sources supplied obsidian to the site. Twelve specimens are attributed to the Ixtepeque source, seven to El Chayal, and one to San Mart�n Jilotepeque. The multiple-source procurement pattern is interpreted as a hedge against the fragility of Postclassic sociopolitical alliances and shifting exchange networks.