BackgroundPrevious studies have indicated that borderline personality disorder (BPD) is closely associated with trauma and dissociation. Nevertheless, BPD is a heterogeneous condition, and not all people with BPD have severe dissociation. This study examined whether the relationship of BPD features with trauma and dissociation would remain significant after controlling for some general non-specific mental health distress. We also made the first attempt to explore which specific BPD features would be particularly associated with dissociation.MethodsWe analyzed survey data from a sample of community health service users in Hong Kong (N= 376). Hierarchical multiple regression and data-driven network analysis were used.ResultsThe lifetime prevalence of DSM-5 BPD was 16.0% in our sample. Of participants who met criteria for BPD, 43.3% scored above cutoff on the dissociation measures, thus possibly having clinically significant dissociative symptoms. BPD features were associated with adulthood trauma and psychoform dissociation even after controlling for age, depression and self-esteem. Network analysis showed that some BPD features – including impulsivity, identity disturbance and suicidal/self-mutilation behaviors – were particularly associated with dissociation; other BPD features such as interpersonal-related problems had relatively weak to no connection with dissociation.ConclusionsOur results suggested that some particular BPD features might be dissociative in nature, although further longitudinal research is required. We argue that a trauma-informed perspective should be employed when working with clients presenting with BPD features despite these features being commonly stigmatized. Further research on the intervention needs of the people with BPD who suffer from high levels of dissociation is required.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40479-023-00228-x.