For individuals who live within the shadows of hazardous waste sites, there is a constant worry about what impact releases from these sites are having on their health and environment. Public health agencies at the local, state, and federal levels are routinely asked to investigate these concerns and determine what, if any, exposures are occurring or may have occurred in the past, and what the health risk to nearby residents may be. To ensure the credibility of research findings, full participation of affected communities is needed. Including communities in research activities can, however, be a difficult process. This paper discusses the concerns, needs, and expectations of U.S. communities in which environmental exposures are occurring, or in which exposures have occurred in the past. Three case studies are presented in which activities were undertaken to involve a community in the research process where environmental contaminants were of concern. The strengths and limitations of these activities are discussed, and recommendations for community involvement in future research are made.