Approximately 73% of patients suffering from Borderline personality disorder (BPD) exhibit aggressive behaviour, which severely hinders therapeutic work and clinical improvement. Because the underlying mechanisms of aggression in BPD are not yet completely understood, additional research in this domain has a high clinical and scientific relevance. We employed a modified version of the Taylor Aggression Paradigm (mTAP), in order to examine for the first time whether this task can be used to differentiate between BPD patients and healthy controls with regard to reactive aggression. In the mTAP, the amount of money subtracted by a virtual opponent was categorized into 'low' (10-20 cents) and 'high' (80-100 cents) provocations, enabling us to compare how much money BPD patients and healthy controls subtracted (i.e., how aggressively participants responded) following high and low provocation trials. Our results showed that, compared to healthy controls, BPD patients showed higher overall aggression, higher aggression after high provocation trials, as well as a larger difference between high and low provocation trials. This finding was corroborated by a neuropsychological assessment, demonstrating higher levels of aggression and impulsivity in BPD patients. Interestingly, reactive aggression in the mTAP was positively correlated with symptom severity and impulsivity in BPD patients. We suggest that the mTAP provides a valuable tool allowing psychiatrists to quantify reactive aggression in BPD. Therefore, clinicians and researchers might consider this task, as a short experimental measure of reactive aggression, either in future studies or to aid diagnostic assessment during clinical practice.