Individuals with borderline personality disorder (BPD) experience emotional instability and have a high suicide rate. Treatment for BPD includes psychotherapy and adaptive emotion regulation strategies, which include cognitive reappraisal. Previous systematic reviews indicate that abnormal brain patterns may cause emotional instability in BPD individuals. To further explore this, this review collected articles that examined neural activity using fMRI during cognitive reappraisal in subjects with BPD and healthy controls. We identified four relevant articles through a search of Web of Science and PubMed. The articles included conflicting results in both participant groups regarding increased or decreased activity during cognitive reappraisal applying either reinterpretation or distancing. The affected brain regions were the following: lateral and ventrolateral prefrontal cortex, left middle temporal gyrus, and superior temporal gyri. Three of the articles reported consistent results of activity in the dorsolateral prefrontal cortex during downregulation, two in all participants and one only in the healthy control group. However, no significant group differences were found in this region during cognitive reappraisal. The discussion includes limitations regarding the comparability of the included studies, such as the method of eliciting negative affect, the use of written or verbal instructions, and the cognitive reappraisal strategy applied. Further research is necessary to better understand the involvement of distinct brain regions in cognitive reappraisal and BPD, as well as to establish more standardized research methods. These efforts can offer comprehensive insights into the neural mechanisms underlying cognitive reappraisal in individuals with BPD.