Drawing on new institutional and market theories, this article derives three hypotheses for the effects of markets on educational organizations: They (1) weaken formal structures, (2) reverse tendencies toward isomorphism, and (3) force schools to recouple and compete via performance indicators. These ideas are investigated with data on private and public schools in Toronto, which, the authors argue, is a strategic research site. The findings vary by market sector. Newer, nonelite private schools seek niches, avoid performance indicators, and dilute formal structures, while older elite schools do the opposite. Thus, market effects on school organizations vary by sector. In conclusion, the authors argue that the impact of markets on schools is mitigated by local institutional conditions. Specifically, the presumed impact of markets on educational quality may be contingent upon certain institutional conditions that, when absent, channel market forces in more consumerist directions.