Extraversion has been associated with positive physical health outcomes, with adaptive cardiovascular responses to stress being one potential physiological mechanism. The present study examined the influence of extraversion on both cardiovascular reactivity and cardiovascular habituation to an acute psychological stress task (Paced Auditory Serial Addition Test (PASAT)) in a sample of healthy undergraduate students.A sample of 467 undergraduate students completed the Big Five Inventory (BFI) to assess trait extraversion and attended a single stress testing session. The testing session included two identical stress-testing protocols, each consisting of a 10-minute baseline and 4-minute PASAT. Cardiovascular parameters including heart rate (HR), systolic/diastolic blood pressure (S/DBP) and mean arterial pressure (MAP) were recorded throughout the testing session. State measures of positive affect (PA) and negative affect (NA), as well as post task measures of self-reported stress were used to assess psychological experiences of the stress task.Extraversion was significantly associated with lower self-reported stress in response to the initial stress exposure, but not the second stress exposure. Higher levels of extraversion were associated with lower SBP, DBP, MAP and HR reactivity in responses to both exposures to the stressor. However, no significant associations were observed between extraversion and cardiovascular habituation to recurring psychological stress.Extraversion is associated with lower cardiovascular reactivity to acute psychological stress and this relationship persists upon repeated exposures to the same stressor. Cardiovascular responses to stress may indicate a potential mechanism facilitating the association between extraversion and positive physical health outcomes.