The Tobacco Prevention Toolkit is a theory-based and evidence-informed educational resource created by educators and researchers aimed at preventing middle and high school students’ use of tobacco and nicotine products.  Developing this Toolkit was accomplished by partnering with key stakeholders (educators, parents, and students), others involved in tobacco or health education, and scientists. We also conducted formative research to inform our curriculum, including holding a series of focus groups with students, health educators, tobacco prevention researchers, leaders within the California Department of Education’s Tobacco Control Branch, and basic scientists focusing on tobacco, e-cigarettes, and addiction, to identify the most important content areas that need to be included, delivery strategies that are engaging for youth, and to obtain the latest evidence known about each tobacco product to ensure that the information presented in our curriculum is accurate.