The present study investigated emotional intelligence (EI) in borderline personality disorder (BPD). It was hypothesized that patients with BPD (n = 61) compared with patients with other personality disorders (PDs; n = 69) and nonpatients (n = 248) would show higher scores on the ability to perceive emotions and impairments in the ability to regulate emotions. EI was assessed with the Mayer-Salovey-Caruso Emotional Intelligence Test (Mayer, Salovey, and Caruso [New York: MHS, 2002]). As compared with the PD group and the nonpatient group, the patients with BPD displayed the anticipated deficits in their ability to understand, whereas no differences emerged with respect to their ability to perceive, use, and regulate emotions. In addition, a negative relationship was found between the severity of BPD and total EI score. However, this relationship disappeared when intelligence quotient was partialled out. These results suggest that BPD is associated with emotion understanding deficits, whereas temporary severity of BPD is associated with emotion regulation deficits.