Differentiating autism spectrum disorders (ASDs) without accompanying intellectual impairment from personality disorders is often challenging. Identifying personality traits and personality pathology specific to ASD might facilitate diagnostic procedure. We recruited a sample of 59 adults with ASD without accompanying intellectual impairment, 62 individuals with narcissistic personality disorder, 80 individuals with borderline personality disorder, and 106 nonclinical controls. Personality traits, measured with the neo-personality inventory-revised (NEO-PI-R), and personality pathology, measured with the dimensional assessment of personality pathology (DAPP-BQ), were assessed. Personality traits and personality pathology specific to ASD could be identified. ASD individuals scored significantly lower on the NEO-PI-R scales extraversion and openness to experience and significantly higher on the DAPP-BQ scales inhibitedness and compulsivity relative to all other groups. Diagnostic implications are discussed.