We discuss some of the lessons the investigators learned during the development, implementation, and dissemination phases of the National Arts and Youth Demonstration Project (NAYDP). The lessons learned are relevant to various groups involved in large-scale, multi-site, community-based intervention studies: parents, youth, researchers, project staff, policy makers, and funders. Specific lessons learned include: (1) how to engage the community; (2) methodological lessons, including cross-site training and monitoring adherence to research protocol; (3) recruiting and sustaining involvement of parents and youth; (4) program development; and (5) dissemination strategies.