'BACKGROUND: Impulsivity is a core feature of borderline personality disorder (BPD). However, previous clinical and experimental studies investigating impulsivity in BPD rendered mixed results. In this study, impulsivity was assessed by self-report scales and behavioral inhibition tasks to compare different data levels. SAMPLING AND METHODS: Fifteen women with BPD and 15 matched healthy control subjects (HC) completed the Barratt Impulsiveness Scale, Eysenck''s Impulsivity Questionnaire and the UPPS (Urgency, Lack of Perseverance, Lack of Premeditation and Sensation Seeking) scale, and participated in a Stroop task, an antisaccade task and a stop signal task. RESULTS: Patients with BPD scored significantly higher on self-report measures as compared to HC, but not in behavioral tests. In BPD patients, but not in HC, behavioral inhibition errors were correlated with more intense emotional state. CONCLUSION: We found a discrepancy between self-report and behavioral data. Further studies need to assess additional possible mechanisms underlying increased impulsivity, their relation to emotional instability, and their neurobiological underpinnings.'