Few studies have investigated the feasibility of researching brief forms of dialectical behaviour therapy (DBT) for borderline personality disorder (BPD) in public mental health settings. This study aimed to provide preliminary evidence for the feasibility of implementing DBT over a 6-month period for BPD symptoms within Australian public mental health services. Of the 79 participants with BPD recruited, 62 commenced and 24 participants completed the therapy. The participants attended one of three outpatient DBT programmes and completed measures of BPD symptoms, DBT skills-use, and difficulties with emotion regulation at baseline and after 6 months of treatment. A major challenge with feasibility identified was the high attrition rate (61%). However, for completers there were significant improvements in BPD symptoms, DBT skills-use, and difficulties with emotion regulation. These effect sizes were used to estimate the sample sizes needed by future larger trials of brief DBT for BPD in public health settings. The implementation of brief DBT for BPD patients within a public mental health outpatient setting, appears to result in significant reductions in BPD symptoms. However, further exploration of strategies to reduce drop-out rates are required.