Objective: Deliberate self-harm (DSH) is common in Borderline Personality Disorder, may be due to a variety of reasons, and is associated with different degrees of suicidal intent. Understanding the reasons for episodes of DSH in this population may be helpful in developing interventions to reduce the rate of DSH or to assist in the clinical judgement of suicidal intention after DSH has occurred. Methods: The Parasuicide History Interview, version 2 (PHI-2) was used to determine the reasons for DSH events in 70 Australian women diagnosed with Borderline Personality Disorder. Factor analysis of the responses identified four empirically derived component factors. Multivariate models were developed to identify the independent predictors of suicidal deliberate self-harm (S-DSH) versus non-suicidal deliberate self-harm (NS-DSH) events. Results: Participants and raters showed strong agreement in classifying S-DSH and NS-DSH events. Methods used that involved self-poisoning, jumping or stabbing showed increased risk for S-DSH, adjusted odds ratio 12.07 (95% CI 2.17, 67.29), compared to the referent group, external damage to skin with no rescue contact being sought. Although no grouping of reasons were independently significant, the lower the effectiveness of the DSH event to resolve the reasons for the event, the higher the risk of it having been a S-DSH event. Conclusion: In clinical situations, any Borderline Personality Disorder patient seeking help or medical attention, using any method other than superficial external injury to skin, or reporting a failure to effectively resolve the reasons for the DSH event, should be considered as likely to have had a S-DSH event (greater suicidal intention). However, specific reasons for the DSH event, or individual subject characteristics, did not meaningfully distinguish S-DSH from NS-DSH events.