Clinical assessment increasingly emphasizes six maladaptive domains of the DSM-5 and ICD-11 trait models, including negative affectivity, detachment, antagonism/dissociality, disinhibition, psychoticism, and anankastia. The present study aimed to validate the Persian version of the ICD-11 compatible Personality Inventory for DSM-5-Brief Form Plus, Modified (PID5BF + M). Data from a mixed sample including 1,615 adults (community N = 1,476 and outpatient N = 139) were used to assess the latent structure, congruence coefficients, reliability, convergent validity, and criterion validity of the PID5BF + M. The results supported the six-factor structure of the PID5BF + M whose traits are largely congruent with those from previous studies. The scale reliabilities were acceptable, and strong associations were observed with personality disorder-type symptom counts (r ranging from .15 to .59, all p < .001). PID5BF + M scales also distinguished clinical and non-clinical samples. The present results support the validity and utility of the PID5BF + M for personality psychopathology screening in the Iranian population.