Opportunities for participation in chronic disease prevention programs are discussed in the context of a description and analysis of the National Cancer Institute's Community Intervention Trial for Smoking Cessation (COMMIT). COMMIT involves 11 matched pairs of communities with random assignment to the intervention condition within each pair. The 4-year intervention is guided by a partly standardized protocol and embodies a number of community psychology principles. The relative congruence of COMMIT with community psychology principles and methods is discussed with particular emphasis on Kelly's (1988) model of community research. Community psychology's participation in chronic disease prevention trials requires understanding of the programmatic framework of National Institutes of Health prevention research and recognition of the constraints imposed by the framework on community psychology practices.