Background The Personal and Social Performance (PSP) scale is a widely used tool to evaluate adults with schizophrenia; however, more studies are needed regarding its usefulness in the assessment of adolescent patients, since the evaluation of their functioning could require adaptations according to development. Objective To examine construct validity, convergent validity, internal consistency and interrater reliability of the PSP in a sample of Mexican adolescents with schizophrenia. Methods A total of 40 patients with a DSM-IV diagnosis of schizophrenia or schizophreniform disorder were evaluated with PSP, CGAS, PANSS and the MATRICS battery. Construct and convergent validity were determined by the correlation between PSP with PANSS factors, MATRICS dimensions and CGAS. In addition, reliability was evaluated with Cronbach's alpha and intraclass correlation coefficients. Results PSP scores correlated with negative, excitement and cognitive factors of PANSS, CGAS as well as MATRICS domains. The PSP also showed high internal consistency and interrater reliability. Conclusions The PSP is a valid and reliable instrument for the assessment of adolescent patients.