 The HSPP intervention was a teacher-led, grades 3-10 tobacco use prevention curriculum plus unit-specific teacher training. There were 65 classroom lessons in the HSPP curriculum: 9 lessons in each of grades 3-5, 10 lessons in each of grades 6-7, 8 lessons in grade 8, and 5 lessons in each of grades 9-10, for a total number of 46.75 hours of classroom instruction time in grades 3-10. The HSPP uses an enhanced social influences approach that includes the 15 NCI-endorsed essential elements for school-based tobacco prevention and meets the CDCs best practices guidelines. The interventions behavioral components featured skills for identifying and resisting social influences to smoke, correcting erroneous normative perceptions regarding smoking, promoting tobacco-free norms, and building self-efficacy for tobacco-free lifestyle choices. The intervention was developed to be practical for the school setting, emphasizing ease of use by teachers, good fit into school routines and with schools existing educational objectives, and incorporation of topicsactivities that are interesting, engaging and developmentally-appropriate for students. 