The National Breast and Cervical Cancer Early Detection Program provides funding to tribes and tribal organizations to implement comprehensive cancer screening programs using a program model developed for state health departments. We conducted a multiple-site case study using a participatory research process to describe how 5 tribal programs implemented screening services, and to identify strategies used to address challenges in delivering services to American Indian and Alaska Native women. We analyzed data from semistructured interviews with 141 key informants, 16 focus groups with 132 program-eligible women, and program documents. Several challenges regarding the delivery of services were revealed, including implementing screening programs in busy acute-care environments, access to mammography, providing culturally sensitive care, and providing diagnostic/treatment services in rural and remote locations. Strategies perceived as successful in meeting program challenges included identifying a "champion" or main supporter of the program in each clinical setting, using mobile mammography, using female providers, and increasing the capacity to provide diagnostic services at screening sites. The results should be of interest to an international audience, including those who work with health-related programs targeting indigenous women or groups that are marginalized because of culture, geographic isolation, and/or socioeconomic position.