Coping flexibility refers to an individual's ability to effectively modify his or her coping behavior to better fit the nature of each stressful situation they encounter. More flexible coping is believed to produce more adaptive psychological functioning and physical health. We examined the relationship between coping flexibility and cardiovascular reactivity (CVR) to psychological stress. Challenging tasks of two difficulty levels were presented to 24 men and 24 women aged 18 to 24years. Heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure were measured. Change scores (from baseline to reactivity) for SBP and HR responses in the difficult task were higher than those in the easy task and were negatively correlated with coping flexibility during the difficult task but not the easy one. The findings suggest that more flexible coping is associated with reduced CVR to a difficult task.