We examined the relationship between acculturation and psychological distress in young (20-30), middle aged (31-50), and older adult (51-74) Mexican Americans (n = 3084). The data were from the Hispanic Health and Nutrition Examination Survey (HHANES). Acculturation was measured with items on spoken and written language and ethnic identification. Psychological distress was measured with the Center for Epidemiologic Studies Depression Scale (CES-D). We found that as acculturation increased, distress significantly increased in young adults but tended to decrease in older adults. This general pattern held for males and females and was consistent for the CES-D total score and caseness rates. The effects of acculturation were independent of the effects of income and education. We discuss that alienation and discrimination may be two intervening events producing the psychological distress of the highly acculturated young adults. Further, our findings tentatively suggest a longitudinal process whereby acculturated younger Mexican Americans attempting to advance themselves economically and socially in the dominant society strip themselves of traditional resources and ethnically-based social support. Through the years, however, they may re-establish ties to their native culture which contributes to relatively positive mental health.