Background Schema-focused therapy (SFT) and transference-focused psychotherapy (TFP) for borderline personality disorder were recently compared in a randomised multicentre trial. Aims To assess the societal cost-effectiveness of SFT v. TFP in treating borderline personality disorder. Method Costs were assessed by interview. Health-related quality of life was measured using EQ-5D. Outcomes were costs per recovered patient (recovery assessed with the Borderline Personality Disorder Severity index) and costs per quality-adjusted life-year (QALY). Results Mean 4-year bootstrapped costs were (SIC)37 826 for SFT and (SIC)46 795 for TFP (95% uncertainty interval for difference -21 775 to 3546); QALYs were 2.15 for SFT and 2.27 for TFP (95% UI -0.51 to 0.28). The percentages of patients who recovered were 52% and 29% respectively. The SFT intervention was less costly and more effective than TFP (dominant), for recovery; it saved (SIC)90 457 for one QALY loss. Conclusions Despite the initial slight disadvantage in QALYs, there is a high probability that compared with TFP, SFT is a cost-effective treatment for borderline personality disorder.