This study examined whether individuals with borderline personality disorder (BPD; N = 25) exhibit deficits in their ability to strengthen their emotion regulation skills over time compared with healthy controls (HCs; N = 30). Participants were instructed to implement 1 of 2 different emotion regulation strategies (i.e., distraction and mindful awareness of the emotion) or to either react naturally (i.e., nonregulation condition) in response to BPD-relevant stimuli across multiple trials. Self-reported negativity and positivity, and physiological indices of emotion were collected throughout. Self-report results indicated that both groups displayed strengthening of distraction, but not mindful awareness, compared with the nonregulation condition over time. When comparing the 2 emotion regulation strategies to each other, heart rate data suggested that the rate of skill strengthening varied by group. Specifically, the BPD group evidenced strengthening of mindful awareness, but not distraction, over time whereas the HCs exhibited the opposite pattern. These findings suggest that individuals with BPD generally do not show deficits in their ability to strengthen emotion regulation skills and exhibit greater strengthening of mindful awareness than distraction over time.