INTRODUCTION: Youth Excel was a 3-year pan-Canadian initiative to advance youth health through improving knowledge development and exchange (KDE) capacity. KDE capacity refers to an improvement cycle linking evidence and action. Capacities include local surveillance of youth behaviours; knowledge exchange; skills, resources and a supportive environment to use knowledge; and evaluation. METHODS: Interviews were conducted with Youth Excel members, including 7 provincial teams and 2 national organizations. Interviews explored participant experiences with building KDE capacity. RESULTS: Local surveillance systems were considered the backbone to KDE capacity, strengthened by co-ordinating surveys within and across jurisdictions and using common indicators and measures. The most effective knowledge exchange included tailored products and opportunities for dialogue and action planning. Evaluation is the least developed KDE component. Building KDE capacity requires frequent dialogue, mutually beneficial partnerships and trust. It also requires attention to language, vision, strategic leadership and funding. CONCLUSION: Youth Excel reinforces the need for a KDE system to improve youth health that will require new perspectives and sustained commitment from individual champions and relevant organizations.