Because stress from marital conflict negatively impacts cardiovascular health, understanding the association between trait mindfulness and cardiovascular functioning in the context of marital conflict may translate into physical health benefits. In this study, data from married couples (N = 90) were collected to examine the intrapersonal and interpersonal associations between trait mindfulness and cardiovascular reactivity in response to a conflict discussion task. Actor–partner interdependence models showed that partners’ individual trait mindfulness scores were significantly related to their own levels of blood pressure during conflict and recovery, and partners’ levels of trait mindfulness were significantly related to their own heart rate variability during conflict discussion but not during conflict recovery. In addition, husbands’ levels of trait mindfulness were significantly related to wives’ cardiovascular reactivity during conflict; likewise, wives’ levels of trait mindfulness were significantly related to husbands’ cardiovascular reactivity during conflict. Findings suggest that higher levels of trait mindfulness may be linked with healthy cardiovascular functioning for individuals and their romantic partners.