Nearly three decades of research have identified evidence of commercial institutions and exchange at cities throughout Mesoamerica. This introduction examines three major areas of investigation for commercial institutions in ancient Mesoamerican cities: marketplaces and urban geography; currencies, standards and credit; and the social dimensions of urban commerce. It discusses the different ways in which the contributing authors examine different commercial economies of ancient Mesoamerica through the prism of its urban centers, and the potential of this approach for further archaeological research.