Participatory mapping and transect walks were used to inform the research and intervention design and to begin building community relations in preparation for Project Accept, a community-randomized trial sponsored by the National Institute of Mental Health. Project Accept is being conducted at five sites in four countries: Thailand, Zimbabwe, South Africa, and Tanzania. Results from the mapping exercises informed decisions such as defining community boundaries and identifying appropriate criteria for matching community pairs for the trial as well as where to situate the services. The mapping also informed intervention-related decisions such as where to situate the services. The participatory methods enabled researchers at each site to develop an understanding of the communities that could not have been derived from existing data or data collected through standard data collection techniques. Furthermore, the methods lay the foundation for collaborative community research partnerships.