Editors' Summary: Nongovernmental organizations and other critics of the North American Free Trade Agreement (NAFTA) have raised serious environmental concerns about Mexico's participation in NAFTA. The U.S. EPA has attempted to address these concerns by evaluating Mexican environmental laws, regulations, and standards. This Article is based on EPA's evaluation and provides a general overview of Mexico's environmental legal system, although its does not review Mexico's state and local environmental laws or its federal mechanisms for environmental law enforcement. The author examines Mexico's environmental government institutions; public participation mechanisms; and approach to environmental impact assessment, air pollution control, water pollution control, waste management, pesticides and toxic substances control, and environmental contingency planning and emergency response. The author concludes that Mexico has established the foundation of a credible legal framework to control environmental contamination, which if fully implemented and enforced, can provide relatively high levels of environmental protection.