The coral reef of Cabo Pulmo is located at the southern tip of the Baja California Peninsula, near the big tourist development in Los Cabos, Mexico. The reef and adjacent areas are highly valued by sport and artisanal fishermen, by aquarium collectors, and by skin and scuba divers from many countries, because it is the most pristine and scenic, and also the most threatened, submarine habitat in Baja California. Research and assessments carried out since 1988 have shown an increasing environmental impact of extractive actions resulting in a decline of coral cover and density of fish, mollusc and other marine populations, generating negative effects in the only coral reef in the Gulf of California. The main purpose of this study was to develop a rigorously planned management strategy to improve the health of the environment and the quality of life of the human population of Cabo Pulmo. The first objective was to evaluate the system and its environmental components as well as the economic and social ones, and their changes in the last 20 years. The methods used included micro region zoning through a Geographical Information System and capacity of use evaluation, integrating the physical, biological, economical and social characteristics of the study area. Based on the evaluation of indexes of fragility, pressure, and vulnerability, 31 environmental units were proposed. Results showed that the predominant environmental policy would be a conservation and protection policy in 48%, sustainable management within 40% of the total area, and restoration in 12%. The sites with the highest human impact would need an environmental management policy, with the encouragement of sustainable tourism, while eliminating and further excluding any extreme use or high density traditional tourism. Many workshops and meetings have been organized to recommend management actions focusing on sustainable tourism and to discuss how to tailor Tourism and Environment 59 www.witpress.com, ISSN 1755-8336 (on-line) WIT Transactions on State of the Art in Science and Engineering, Vol 69, © 2013 WIT Press doi:10.2495/978-1-84564-808-4/006 specific features. After more than 20 years, a recent evaluation of this coralline system, now a National Park, demonstrated that the quality of life of the local inhabitants has improved, and that there is a healthier ecosystem, with coral recovery, many sea turtles, whales, sharks, other fish and invertebrates.