A broad range of psychotherapies have been proposed and evaluated in the treatment of borderline personality disorder (BPD), but the question which specific type of psychotherapy is most effective remains unanswered. In this study, two network meta-analyses (NMAs) were conducted investigating the comparative effectiveness of psychotherapies on (1) BPD severity and (2) suicidal behaviour (combined rate). Study drop-out was included as a secondary outcome. Six databases were searched until 21 January 2022, including RCTs on the efficacy of any psychotherapy in adults (⩾18 years) with a diagnosis of (sub)clinical BPD. Data were extracted using a predefined table format. PROSPERO ID:CRD42020175411. In our study, a total of 43 studies (N= 3273) were included. We found significant differences between several active comparisons in the treatment of (sub)clinical BPD, however, these findings were based on very few trials and should therefore be interpreted with caution. Some therapies were more efficacious compared to GT or TAU. Furthermore, some treatments more than halved the risk of attempted suicide and committed suicide (combined rate), reporting RRs around 0.5 or lower, however, these RRs were not statistically significantly better compared to other therapies or to TAU. Study drop-out significantly differed between some treatments. In conclusion, no single treatment seems to be the best choice to treat people with BPD compared to other treatments. Nevertheless, psychotherapies for BPD are perceived as first-line treatments, and should therefore be investigated further on their long-term effectiveness, preferably in head-to-head trials. DBT was the best connected treatment, providing solid evidence of its effectiveness.