Aim/background: There is a lack of psychometric instruments to measure psychopathology in people with intellectual disabilities (ID). This may lead to underdiagnosis of treatable psychiatric comorbidities in this population. Psychiatric assessment schedule for adults with developmental disabilities (PAS-ADD) Checklist was developed as a screening tool designed for lay people. The PAS-ADD Checklist was created in English and was later on validated for other languages, including French and German. There is no psychometric measure available in Turkish to screen for or detect psychiatric symptoms in adults with ID. The aim of the present study was to present a psychometric evidence of the Turkish language version of the PAS-ADD Checklist. This is the first study aiming to present and validate a psychiatric screening instrument for adults with ID in Turkey.