The assessment of personality pathology based on dimensional models may improve self-other agreement, but previous research mainly adopted a categorical approach and overlooked the role of the person of the therapist. Our study examined patient-clinician agreement in a mixed sample of Italian outpatients using the Personality Inventory for DSM-5 (PID-5) and the PID-5-Informant Form (PID-5-IRF). Moreover, the role of clinician personality traits on agreement was preliminary explored. Sixty-eight outpatients (51.4% male, M = 30.30, SD = 12.05 years) and their treating clinicians (N = 22; 77.3% female, M = 43.77 ± 8.45 years) entered the study. Patients completed the PID-5, whereas clinicians filled-in the PID-5-Brief Form (PID-5-BF) and the PID-5-IRF for each patient they involved. A multilevel Bayesian analysis showed that rank-order agreement was large for domains (mean r = .60) and moderate for facets (mean r = .44). As regards mean-level agreement, patient ratings on cognitive/perceptual dysregulation, distractibility, eccentricity, and emotional lability were higher than clinician ratings, whereas patients' scores on depressivity were lower than clinicians' ones. Scores on the PID-5-BF detachment positively predicted agreement on anhedonia, anxiousness, depressivity, distractibility, separation insecurity, and suspiciousness, while scores on the PID-5-BF negative affectivity, antagonism, and disinhibition negatively predicted agreement on few specific facets. Current findings suggest that clinician personality traits may contribute to agreement on maladaptive personality traits, but areas of discrepancies remain in case of low observable internal ones. Since patient-clinician agreement is crucially involved in therapeutic alliance, further research on this issue is highly encouraged. (PsycInfo Database Record (c) 2024 APA, all rights reserved).