A 15-item questionnaire used to evaluate competency to consent to psychiatric hospitalization was validated using a blind forensic psychiatric interview. The statistical correlation was excellent with p < .001. The questionnaire also correlated highly with the Mini-Mental State exam (p < .05), the Brief Psychiatric Rating Scale (p < .05), and the Weschler Adult Intelligence Scale-Revised vocabulary subtest (p < .01). This questionnaire may be a useful instrument for preliminary screening of psychiatric patients for competency to consent to hospitalization and general psychiatric treatment.