This paper describes the development of the American Indian Oncology Program (AIOP) and presents the accomplishments of a participatory research approach that involved an integrated network for cancer care and research. AIOP used a participatory process to develop infrastructure, identify research questions, develop methodologies, write supplemental grants, and evaluate accomplishments based on community defined measures of success. Partnerships between University and Indian Health Service, private, and state institutions led to improved collaboration. Health services delivery improved by increasing provider involvement at multiple institutions via a Tumor Board. Community awareness improved through workshops addressing community-specific cancer concerns. Collectively, these resulted in an environment receptive to the development of research activities. The AIOP team, through a participatory process, developed infrastructure at each institution that facilitated interaction, community-based education, and improved patient care; identified new partners; raised community-level knowledge and awareness about cancer; encouraged a research-friendly environment and building research capacity; and increased the cultural competency of researchers wishing to work in American Indian communities and created a cadre of future American Indian cancer researchers. As evidenced by successful pilot project development and formation of ongoing research and funding applications, the authors created a research-receptive environment and promoted potentially sustainable research capacity in the community. Much of their success is the result of utilizing a participatory model for capacity building that included not only communities but institutions. Cancer 2006. Published 2006 by the American Cancer Society.