Purpose: Healthy Habits, Healthy U (HHHU) is a two-day school-based primary prevention cancer education program that uses interactive classroom presentations designed to help students learn how to reduce their cancer risks. HHHU is a collaboration between a local cancer hospital, school district and university. HHHU incorporates real cancerous and non-cancerous specimens to help students see cancer's impact on the body. The purpose of this formative evaluation was to revise the program based on feedback from the students, teachers, facilitators and research assistants. Methods: Two studies, fall and spring, were conducted to assess the efficacy of the HHHU junior high cancer prevention program. Eight hundred thirteen students participated in Study 1 and eight hundred twenty participated in Study 2. Results: The results indicated that students learned how lifestyle choices affect the body, what cancer is and how it develops. Students could identify three of their unhealthy habits that might increase their risk for cancer as well as how they could make changes to these unhealthy habits in the next 30 days to decrease their risk of cancer. Feedback from students, teachers and the HHHU team was used to make program improvements for Study 2. Conclusions: The results of Study 1 and Study 2 suggest that students' knowledge of cancer, how cancer develops, and ways everyday lifestyle choices affect the risk of developing cancer have improved following program implementation. Incorporating participant feedback improved program delivery and student worksheets. Recommendations: Ask students to create a plan to improve an unhealthy habit and conduct a follow-up with students at the end of the semester. Continue to refine the program and expand to additional urban and rural schools. Add an elementary school version of the program.