OBJECTIVE: To examine the association between psychosocial stress and diabetes in two American Indian reservation communities (Northern Plains and Southwest). RESEARCH DESIGN AND METHODS: The American Indian Services Utilization, Psychiatric Epidemiology, Risk and Protective Factors Project (AI-SUPERPFP), a cross-sectional probability sample survey, interviewed 3,084 randomly selected members of two American Indian tribal groups. Included were a psychiatric epidemiological interview, a physical health problems checklist, and an extensive sociodemographic section. RESULTS: Stress was common in these reservation communities, and the stress burden was greater among those with diabetes. After adjusting for sociodemographic characteristics, early-life interpersonal trauma and community family dysfunction were significantly associated with increased odds of diabetes in the Northern Plains, while discrimination and community addiction problems were significantly associated with increased odds of diabetes in the Southwest. CONCLUSIONS: A number of psychosocial stresses were significantly associated with increased odds of self-reported diabetes in these two American Indian communities.