Borderline personality disorder (BPD) includes a heterogeneous constellation of symptoms operationalized with 9 categorical criteria. As the field of personality disorder (PD) research moves to emphasize dimensional traits in its operationalization, it is important to delineate continuity between the 9 DSM-IV/Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) categorical criteria for BPD and the trait dimensions in DSM-5 Section III. To date, no study has attempted such validation. We examined the associations between the 9 categorical DSM-IV/DSM-5 criteria for BPD and the trait dimensions of the alternative DSM-5 model for PDs in consecutively recruited psychiatric outpatients (N = 142; 68% female; age: mean 29.02, SD 8.38). This was investigated by means of bivariate correlations, followed by multiple logistic regression analysis. The categorical BPD criteria were associated with conceptually related DSM-5 Section III traits (P > 0.001), except for the criterion of chronic feelings of emptiness. Consistent with the proposed traits criteria for BPD in DSM-5 Section III, we found Emotional lability, Anxiousness, Separation insecurity, Depressivity, Impulsivity, Risk taking, and Hostility to capture conceptually coherent BPD categorical criteria, while Suspiciousness was also strongly associated with BPD criteria. At the domain level, this applied to Negative affectivity, Disinhibition, and Psychoticism. Notably, Emotional lability, Impulsivity, and Suspiciousness emerged as unique predictors of BPD (P > 0.05). In addition to the proposed BPD traits criteria, Suspiciousness and features of Psychoticism also augment BPD features. Provided that these findings are replicated in forthcoming research, a modified traits operationalization of BPD is warranted.