Evaluation. Based on input from elicitation studies, focus groups with adolescents and mothers, a pre-intervention survey of 668 mother-adolescent pairs, a psychometric study for both English- and Spanish-language instruments, feedback from community and school leaders, and a scientific panel of experts, the instruments, manuals and intervention protocol have been developed. All measures and intervention materials have been developed in English and in Spanish. The evaluation includes a baseline, 3-month post-test and a 15-month delayed post-test assessment of adolescents and mothers. For tobacco, within schools, students will be randomly assigned to an experimental group (school-based curriculum plus parent component) or a control group (school-based curriculum only). For sexual risk reduction, students will be randomly assigned to the combined experimental condition (school-based curriculum plus parent component), a parent-only experimental condition (parent component is distributed to mothers, but no school component is delivered) or a control group (school-based curriculum only).