Mesoamerican copper metallurgy emerged in Western Mexico between AD 600 and 800. Over a period of approximately 900 years a wide variety of artefacts, typically decorations and other valuable non-utilitarian goods, were produced. By AD 1450, the Tarascan kingdom in the state of Michoacan had become the most important center of pre-Hispanic metalworking. Metallurgy played a significant role in the structure of political and economic power in the Tarascan Empire. Archaeological research at the site of Itziparátzico, near the modern Tarascan community of Santa Clara del Cobre, has recently located potential production areas where concentrations of smelting slag were recorded. Slag analysis has the potential for revealing important information about metallurgical technology. Copper smelting slag recovered from the excavations at Itziparátzico has been analyzed for microstructure and compositional properties using light microscopy, x-ray fluorescence spectrometry (XRF), and scanning electron microscopy with energy-dispersive x-ray spectrometry (SEM/EDS). Preliminary results indicate a smelting technology that used sulfidic ores and highly efficient furnaces. While further archaeological investigations are required to precisely date these activities, this technological information is important for establishing the context and scale of production of copper at the site. -- ICCROM