Introduction. - Borderline Personality Disorder (BPD) is a severe psychiatric disorder and is associated with significant impairment in quality of life. The aim of the present study is to assess the internal and external responsiveness of the EuroQoL-5D (EQ-5D) in BPD patients. Patients and Methods. - Data from 49 patients included in a multi-center Dutch randomized trial were used. We used both the EQ-5D utility score and the Visual Analogue Scale of the EuroQoL, and the Borderline Personality Disorder Severity Index-IV (BPDSI-IV). To determine internal responsiveness, we calculated the standardized response mean (SRM). To determine external responsiveness, we calculated Spearman correlations for the change scores, and compared EQ-5D scores for clinically improved vs. non-clinically improved patients as measured with the BPDSI-IV. Results. - Patient scores improved on all instruments during the three years. SRMs for BPDSI-IV were significantly higher than EQ-5D utility. Three-year Spearman correlation between change scores of BPDSI-IV and EQ-5D utility was 0.487, between BPDSI-IV and EQ-VAS it was 0.404, both statistically significant. EQ-5D utility scores for patients who clinically improved were significantly higher than for patients who did not. Discussion. - We conclude that the EQ-5D is fairly responsive in BPD, and, therefore, especially because of its brevity and user-friendliness, can serve as a useful tool in economic evaluations in patients with BPD.