Although an estimated 20% of adult cancer patients are medically eligible for a cancer treatment clinical trial (CCT), adult trial participation in the U.S. remains under 3%.- Participation rates are even lower among ethnic and racial minorities and the medically underserved, who tend to have higher cancer mortality rates than the population as a whole.- Given persistent cancer health disparities in these populations, cancer clinical trial participation is increasingly an issue of social justice. Community-based participatory research (CBPR) approaches have been repeatedly recommended as a key strategy for increasing and diversifying cancer clinical trial participation and enhancing their relevance and quality. In 2006, Community-Campus Partnership for Health (CCPH) and the Education Network to Advance Cancer Clinical Trials (ENACCT) received funding from the Agency for Healthcare Research and Quality and the National Cancer Institute (NCI), along with industry and nonprofit partners, to develop the first set of national recommendations to employ CBPR approaches in multisite, phase III cancer clinical trials. The Communities as Partners in Cancer Clinical Trials: Changing Research, Practice and Policy final report, developed through a national advisory committee, two stakeholder meetings and a public vetting process, makes more than fifty detailed recommendations to engage communities in specific and meaningful ways throughout the cancer clinical trial process.1 The report is the first to provide specific guidance as to how and why clinical trials should involve communities affected by cancer-from trial design to implementation to dissemination of results. This paper describes the background and rationale for the initiative, the process used to develop and disseminate the report, and the challenges and opportunities for implementing the report's community-based approaches to cancer clinical research.