School-based wellness courses are an opportunity to help adolescents attain better health and reach their academic potential by providing the knowledge, skills, social support, and environmental reinforcement needed for adoption of long-term health and wellness behaviors. While courses vary widely, schools commonly integrate a yearlong wellness/health course with physical education. This is typically the only required course during high school that teaches students about lifestyle and behavior choices and their relationship to health and disease. The impact of these wellness courses on adolescent knowledge and application is not known, nor is it known to what extent students retain that knowledge during high school. PURPOSE: This study examined the effect of a 9th grade wellness curriculum on adolescent wellness knowledge gain and retention during high school. METHODS: Health and wellness knowledge and behavior application in the areas of alcohol, tobacco, other drugs; physical fitness; medical/ cardiovascular risk factors; nutrition; and psychological/social were assessed using a 72-item test including 4 demographic questions. Subjects were ninth grade students enrolled in a mandatory wellness/physical education class. This class fulfilled both the state requirement for health and the freshmen requirement for physical education. Assessment tests were administered at the start (fall 2000, pre-test, N=311) and end of the freshman year (spring 2001, N=273), and again at the end of their senioryear (spring 2004, N=239). RESULTS: The pretest score was 37.5 + 9.9 (mean + S.D.) out of a possible 68 questions, or 55% correct, whereas the mean score at the end of the freshman wellness course was 45.5 + 9.5 or 67%, a 21.3% improvement. The post-test score at the end of the senior year was 45.6 + 11.6 or 67%. CONCLUSION: The senior year test results indicate that health and wellness knowledge did not increase during the remaining high school years, with the mean test score remaining at 67%. This level of knowledge may hinder students in making wise choices that reduce disease following high school and throughout life. This study demonstrates the need for continued health education after the freshman year. Ideally, health and wellness knowledge and skills would be reinforced in physical education classes throughout the high school years to provide students with the tools necessary to make healthful lifestyle choices and improve their lifetime health and wellness. Funded by IL Office of Attorney General, Vitamin Anti-Trust Settlement and IAHPERD Jump Rope for Heart Program.