Vietnamese immigrants tend to cluster in targeted geographic areas and occupations with resulting disproportionate exposure opportunities to hazardous environmental chemicals and neighborhood stressors; yet there is little research on environmental health in this population. Vietnamese communities in Alameda, Marin, Santa Clara, and Orange counties in California conducted community mapping audits (i.e., collecting air-contaminant data, observational survey information, and photovoice documentation) in neighborhoods where they live, work, and play. This paper describes the community-based participatory research process that helped to raise awareness about the environment for participating communities, and looks at how community engagement can lead to action for change.