This study was conducted to examine the association between marital adjustment and psychological distress in a large, probability sample of married adults in Japan (N = 710) from the Midlife Development in Japan study. Results indicate that positive and negative dimensions of marital adjustment were significantly associated with dimensional and categorical measures of psychological distress. Furthermore, the associations between marital adjustment and psychological distress remained significant when statistically controlling for neuroticism, quality of friend and family relationships, and demographic variables. These results demonstrate that the well-established association between marital adjustment and psychological distress found in European American countries is also found in Japan. Findings support continued research on marital functioning and psychological distress in East Asian countries.