This proposal is being submitted in response to RFA-TW-11-003, the third round of Fogarty's International Tobacco and Health Research and Capacity Building Program. The research goal of this project is to design, deliver, and evaluate a culturally-appropriate, coordinated, multiple component intervention to prevent and reduce tobacco use among adolescents in Montevideo, Uruguay. The intervention, called ¿Act¿vate!, will be grounded in evidence-based intervention strategies known to prevent and reduce tobacco use among young people in high-income (e.g., United States) and low-income (e.g., India) nations, "translated" for use in this middle-income country. Additional intervention strategies wil be employed to encourage and support physical activity, given new studies that suggest that promoting physical activity could actually prevent tobacco use. Given the comprehensive regulatory environment that currently exists in Uruguay and our use of the existing evidence-base and essential elements therein, we anticipate short- and long-term effects on tobacco use and will test for that. The efficacy of the intervention will be evaluated in a group-randomized, controlled trial that will follow a cohort of 3,200 youth in Montevideo, Uruguay over 3 years. Capacity building will be an integrated and significant part of our research program. Capacity building strategies will provide multiple training opportunities for public health professionals in Uruguay and the United States to suitably apply and enhance their skills specific to designing, implementing, and monitoring behavioral interventions for Latin American youth and conducting and evaluating large-scale research studies with adolescents. Capacity building activities will also engage and activate young people, their parents, and other community members to take action to prevent the onset and progression of tobacco use among adolescents in Uruguay. The US-based team is with the School of Public Health, University of Texas. They are well-positioned to lead this study, having been successful recipients of Fogarty funding in the previous two rounds of this mechanism. The Uruguay-based team is with CIET, the Tobacco Epidemic Research Center in Uruguay. CIET is at the forefront of tobacco control research, practice, and advocacy in Uruguay (and across the region of Latin America), well-known for their work with civil society and government officials, both locally and internationally.