This longitudinal study investigated the predictive value of trauma and mental health problems for the development of antisocial personality disorder (ASPD) and borderline personality disorder (BPD) in previously detained women. The participants were 229 detained adolescent females who were assessed for traumatic experiences and mental health problems (mean age = 15.5 years). Three to 6 years later (M = 4.5; SD = 0.6), ASPD and BPD were diagnosed with a semistructured interview. Forty percent of the women had a personality disorder (i.e., ASPD 15.8%, BPD 9.2%, or both ASPD and BPD 15.2%). Posttraumatic stress, depressive symptoms, and dissociation during detention increased the risk for BPD in adulthood. Surprisingly, neither conduct problems nor substance dependence predicted ASPD; these findings require further study because they add to the controversy surrounding ASPD in females. The high prevalence rates of personality disorders indicate the need for intervention programs that target these unwanted outcomes.