Emotional dysfunction is a key feature of patients with borderline personality disorder (BPD) but emotional intelligence (EI) has rarely been investigated in this sample. This study aimed at an investigation of ability EI, general intelligence, and self-reported emotion regulation in BPD. We included 19 patients with BPD and 20 healthy control subjects in the study. EI was assessed by means of the Mayer-Salovey-Caruso emotional intelligence test and the test of emotional intelligence. For the assessment of general intelligence, we administered the multidimensional "Leistungsprüfsystem-Kurzversion." The emotion regulation questionnaire and the difficulties in Emotion Regulation Scale were used to assess emotion regulation. The patients with BPD did not exhibit impairments of ability EI and general intelligence but reported severe impairments in emotion regulation. Ability EI was related both to general intelligence (patients and controls) and to self-reported emotion regulation (patients). In conclusion, emotional dysfunction in BPD might primarily affect self-perceived behavior rather than abilities. Intense negative emotions in everyday life may trigger dysfunctional emotion regulation strategies in BPD although patients possess sufficient theoretical knowledge about optimal regulation strategies.