Objectives The present study investigated deficiencies in different components of emotional intelligence in borderline personality disorder (BPD). Method The Mayer–Salovey–Caruso Emotional Intelligence Test (MSCEIT) and the Emotional Quotient Inventory (EQ‐i) were used to assess EI dimensions. BPD patients (N = 85; 69 women; M = 33.6 years) were compared with Cluster C personality disorder (PD) patients (N = 39; 23 women; M = 36.6 years) and nonpatients (N = 69; 44 women; M = 35.6 years). Results Compared to the Cluster C PD patients and the nonpatient group, BPD patients displayed only deficits in their ability to understand emotions as measured with the Mayer–Salovey–Caruso Emotional Intelligence Test. The Emotional Quotient Inventory only revealed deficits in stress management in BPD patients compared to Cluster C PD patients. Conclusions Our findings suggest that BPD patients have the ability to regulate emotions effectively, but they subjectively experience deficits in emotion regulation and therefore may not use this ability when they need it.