Personality disorder (PD) is particularly common in adolescents, which underscores the significance of early screening, diagnosis, and intervention. To date, the definition of PD in the new ICD-11 has not yet been investigated in adolescents. This study therefore aimed to investigate the unidimensionality and criterion validity of self-reported ICD-11 PD features in Peruvian adolescents using the Personality Disorder Severity ICD-11 (PDS-ICD-11) scale. A total of 1,073 students (63% female; age range 12-16 years) were administered the PDS-ICD-11 scale along with criterion measures of personality pathology and symptom distress. The PDS-ICD-11 score showed adequate unidimensionality and conceptually meaningful associations with external criterion variables. The findings indicate that ICD-11 PD features, as measured with the PDS-ICD-11 scale, are structurally and conceptually sound when employed with adolescents. Norm-based cutoffs derived from the present study may be used for clinical interpretation. The PDS-ICD-11 may be employed as an efficient screening tool for personality dysfunction in adolescents.