This article examines the social organization of Latino migrants who openly sell their labor at the street-corner, labor markets in the Los Angeles metropolitan area. In contrast to the characterization of day-labor sites as competitive or unstructured, this study demonstrates that these markets have a variety of structural forms that provide the organizational basis for bringing together prospective employers and seekers of work, the esquineros. Like all other markets, the day-labor market has customs and rules that apply as participants seek efficiency in dealing with each other and with their clients. The rules are unwritten and based largely on practice or precedent, but they govern many aspects of the work relationships, including the wage relationship. This study found that day-labor markets respond less to competition and more to informal work rules and to the role of customary relationships.