Developmental antecedents of borderline personality disorders (BPDs) were examined in 25 DSM-IV-diagnosed subjects with BPD and 107 non-borderline control subjects on the basis of medical records and 28 years follow-up. Abuse, neglect, environmental instability, paternal psychopathology, and lower score on protective factors differentiated significantly between the groups. Environmental instability and lower score on protective factors such as artistic talents, superior school performance, above average intellectual skills, and talents in other areas were found to be independent predictors of BPD diagnosis. The results of this study suggest that both abuse and neglect, unpredictable and unstable early environment, as well as deficit in protective factors may substantially contribute to the development of BPD in persons constitutionally predisposed for the disorder. The results of the study also suggest that future research should address the impact of social and cultural context, as well as the absence of protective factors, on the development of the BPD.