This article examines a large cohort of previously suicidal adolescents, identifying those that surpassed threshold criteria for borderline personality disorder (BPD), according to the Abbreviated Diagnostic Interview of Borderlines (Ab-DIB), and determining the stability, correlates and predictors of BPD from early-to-late adolescence. Two hundred and eighty-six youth (mean baseline age 14.6 years; SD 1.5), presenting consecutively to a metropolitan pediatric hospital emergency department for evaluation of suicidality, were assessed at initial consultation for Axis I and II disorders and demographic and clinical variables. Two hundred and twenty-nine (80%) were re-assessed for those variables 4 years later and 204 (70.3%) had complete data sets at recruitment and follow-up. Previously suicidal youths who met BPD threshold on the Ab-DIB at recruitment were distinguishable at baseline from those who did not in conduct disorder symptoms (p < 0.003), lower levels of functioning (p < 0.001), drug use (p < 0.001), stressful life events (p < 0.003) and family relations (p < 0.001). The BPD diagnosis was consistent, according to this measure, at baseline and follow-up for 76% of participants. Four groups with respect to borderline pathology (persisting, remitting, emerging and never) were identified (ICC = 0.603, 95% CI = 0.40-0.78). Persistent BPD status was predictable by older age at presentation (p < 0.01) and level of functioning (p < 0.05). Eight percent were also suicidal at the 4-year follow-up. Using a self-report measure of BPD, we suggest that suicidal youth can indeed be diagnosed with the disorder at 14 years old, supporting the shift from DSM-IV to DSM-5, given what appears to be its temporal stability, differentiation of those suffering with considerable symptomatology or not, and predictors of its status in late adolescence. The low suicidality rate at follow-up indicates a good short-term prognosis.