Community-based participatory research directly involves community members and community-based service providers as partners in the research process. It is especially important in Native American communities, where egregious research practices have led some communities and individuals to be wary of researchers. Messengers for Health uses a lay health advisor (LHA) approach. The purpose of this article is to report the methods and results of a process evaluation of LHA training for a cervical health project. The authors also provide evaluation information on the advisers' perceptions of other LHAs involved in the project and their ideas on what the project could do to be more supportive. This article is intended to be useful to programs working with Native American communities and individuals, to interventions that use community members for outreach and/or education, or to any program interested in using process evaluation. Process evaluations usually focus on program activities and are an essential component of health education programs. These evaluations provide quality assurance, help program directors modify future training programs, and make available practical and useful answers to questions that cannot be answered by outcome evaluation alone. In this article, the authors organized a training workshop to provide Messengers (the LHAs) with knowledge about cervical health, skills to plan and carry out cervical health outreach activities, information about other health issues affecting Native women, and the opportunity to come together with others desiring to help all Apsaalooke women become healthier. They used tape-recorded interviews to collect data, asked questions about the training to gain general perception, how the training could be improved, what new skills they gained from the training, what topics they wanted more training, perceptions of other Messengers, making the project more supportive and Messengers' perceptions of presenters. Furthermore, the authors discuss implications from the evaluation. These lessons are to incorporate culture into training programs; assess the best method of delivery for these training programs; involve community members in the research process; and elucidate training goals and assumptions and use process evaluation to assess outcomes. (Contains 57 notes.)