After the introduction of histrionic personality disorder (HPD), nosologists struggled to reduce its overlap with borderline personality disorder and other PDs. We studied the coherence of HPD in adults and adolescents as part of 2 larger studies. Clinicians described a random patient with personality pathology using rigorous psychometrics, including the SWAP-II (a Q-sort that captures personality and its pathology in adults) in study 1 and the SWAP-II-A (the adolescent version) in study 2. Using DSM-IV-based measures, we identified patients who met HPD criteria with varying degrees of diagnostic confidence. Central tendencies in the SWAP-II and SWAP-II-A profiles revealed that both the most descriptive and most distinctive features of the patients included some features of HPD but also many features of borderline personality disorder. Q-factor analyses of the SWAP data yielded 3 types of patients in each of the 2 samples. The HPD diagnosis may not be sufficiently coherent or valid.