Previous survey of the Toltec site of Tula, Hidalgo, Mexico, revealed what is believed to have been a zone of obsidian workshops within the Early Postclassic city. Tulane University conducted excavation of part of one topographic complex within the zone, revealing a workshop complex consisting of a linear arrangement of residential compounds, peripheral refuse dumps, and open work areas, the latter tentatively identified by microscopic analysis of soil samples. Over 500,000 pieces of obsidian were recovered, revealing an exclusively core/blade industry that imported percussion macrocores from at least two different sources and produced prismatic blade cores, blades, and certain blade products. The reduction sequence and differences in the processing of obsidian from different sources are well documented. Ceramic and stratigraphic data suggest the locality was originally marginal land settled relatively early in Tula's history, possibly by immigrants from the Basin of Mexico.