BACKGROUND: Cardiovascular disease (CVD) remains a key cause of mortality worldwide. Prior work has found that the association between stress and cardiovascular outcomes is moderated by emotion regulation (ER) and expressive suppression (i.e., emotion inhibition), which is linked with adverse outcomes (i.e., inflammation) in Western (Americans) but not Eastern (Japanese) populations. Existing cultural differences in biological stress responses and suppression use suggest that these factors may have different implications for CV outcomes. OBJECTIVE: We address this gap in the literature by examining if ER differentially moderates the relationship between stress and CVD risk between Japanese and American adults. METHOD: Participants were from the Midlife in Japan and Midlife in the United States studies and had complete biomarker and psychological data (Japanese: RESULTS: Adjusting for age, sex, education, tobacco, alcohol, and prescription medication use, linear regressions revealed robust cultural differences among those with high suppression ( CONCLUSIONS: Consistent with prior work, these findings suggest that adaptive ER moderates the association between stress and CVD risk, and that suppression may not be universally 'maladaptive.' Results emphasize the importance of considering cultural context when assessing the impact of emotion suppression on health, which may help explain differences in CVD outcomes between individuals from Eastern and Western populations.