Objective: To assess the effectiveness of an adolescent peer-led health curriculum in changing physical activity and fruit and vegetable social-cognitive and behavioural variables among Filipino American adolescents in Hawai'i for participants and peer educators. Design: Quasi-experimental design. Setting: One high school on Oahu, Hawai'i. Method: Filipino American adolescents aged 16-18 years from a grade 12 health class were recruited and trained as peer educators to deliver a health curriculum to grades 9-11 health classes over 8 months. We examined peer educators' influence on physical activity and fruit and vegetable social-cognitive (knowledge, stage of change, self-efficacy and enjoyment) and behavioural variables (physical activity and consumption). Participants and peer educators completed baseline and follow-up questionnaires. Results: Compared with controls, intervention students showed an increase in physical activity knowledge and self-efficacy. Multiple regression analysis predicted higher physical activity knowledge and moderate-vigorous physical activity follow-up scores for members of the intervention group. A significant effect was found for physical activity stage of change and moderate-vigorous physical activity for peer educators over time. No significant effect was found for any fruit and vegetable variables. Conclusion: A peer-led health curriculum may be a viable method to change physical activity social-cognitive and behavioural variables in Filipino American adolescents and peer educators.