Purpose: Adults presenting with borderline personality disorder (BPD) score poorly on measures of health related quality of life (HRQoL). Little is known about HRQoL in adolescents with BPD type presentations and how treatment impacts quality of life. Our primary aim was to use routinely collected quality-of-life outcome measures pre and post-treatment in dialectical behaviour therapy (DBT) for adolescents to address this gap. Secondary aims were to benchmark these data against EuroQol 5 dimensions (EQ-5D (TM)) outcomes for clients treated in clinical trials and to assess the potential of the EQ-5D (TM) as a benchmarking tool. Method: Four adolescent DBT teams, routinely collecting outcome data using a pseudonymised secure web-based system, supplied data from consecutive discharges. Results: Young people in the DBT programmes (n = 43) had severely impaired HRQoL scores that were lower at programme admission than those reported in published studies using the EQ-5D (TM) in adults with a BPD diagnosis and in one study of adolescents treated for depression. 40 % of adolescents treated achieved Reliable Clinical Change. HRQoL improved between admission and discharge with a large effect size. These results were not statistically significant when clustering in programme outcomes was accounted for. Conclusion: Young people treated in NHS DBT programmes for BPD type presentations had poorer HRQoL than adults with a BPD diagnosis and adolescents with depression treated in published clinical trials. The EQ-5D (TM) detected reliable change in this group of adolescents. Programme outcome clustering suggests that both the measure and the web-based monitoring system provide a mechanism for benchmarking clinical programmes.