Type II diabetes mellitus (NIDDM) is used as a model in examining neuroendocrine and experiential linkages between social inequality and health outcome. Ethnographic, psychosocial, and biochemical data collected among Mexican-American migrant farmworkers reveal that diabetic workers spent more years in migrant labor (p < .01), and reported a greater number of stressful life events (p < .001), than nondiabetics. Body mass index (BMI) did not differ significantly between the two groups. Dopamine-beta-hydroxylase, a regulating enzyme in the stress-responsive catecholamine system, may contribute to diabetes risk for some individuals; other pathways for neuroendocrine mediation of psychosocial stress are discussed. It is proposed that the oppressive life conditions of migrant farmworkers contribute to adverse health outcomes through specific physiological responses to life experiences.