BACKGROUND AND OBJECTIVES:There has been a recent proliferation of research evaluating the efficacy of mindfulness as a clinical intervention. However, there is still little known about trait mindfulness, or how trait mindfulness interacts with maladaptive emotion regulation strategies. The current study further explores the effect of trait mindfulness on emotion regulation, as well as whether specific factors of trait mindfulness are uniquely associated with subjective and autonomic reactivity to stress. METHODS: Forty-eight healthy male participants were trained in the use of the suppression strategy and then instructed to suppress their responses to the inhalation of a 15% CO2-enriched air mixture for 90 s while their subjective distress and heart rate were recorded. RESULTS: After controlling for anxiety-related variables, the ability to provide descriptions of observed experiences predicted less heart rate reactivity to CO2 inhalation, while skillfulness at restricting attention to the present moment was uniquely predictive of less subjective distress. The tendency to attend to bodily or sensory stimuli predicted greater distress during CO2 inhalation. LIMITATIONS: The inclusion of only healthy males limits the generalizability of study findings. Also, the sample size was relatively small. CONCLUSIONS: These findings suggest that factors associated with trait mindfulness predict less stress reactivity and distress while engaging in suppression above and beyond other variables that have been shown to predict anxious responding. The implications for emotion and clinical research are discussed.