Background: AUDIT is constructed to be able to identify hazardous drinking and less severe alcohol-related problems. The original AUDIT was shown to have a cut-off score of 8 and above for identifying hazardous or harmful alcohol consumption. The aim of this study was to establish the optimal cut-off point of the Persian version of Alcohol Use Disorders Identification Test (AUDIT) in psychiatric out-patients. Methods: Participants were a sample of consecutive patients at Imam Hossein Hospital (Tehran/Iran). They consisted of 99 patients, 49 of them diagnosed with alcohol dependency and 50 patients who randomly selected from a sample of patients using alcohol but with other primary diagnoses. All statistics including means and standard deviations as well as medians and interquartile range were calculated in SPSS.24 software environment. Results: A Receiver Operating Curve analysis showed that by using a cut-off 20 points, AUDIT had an optimal combination of sensitivity (.92) and specificity (.74). The rate of discrimination was .88. Conclusions: Given the high sensitivity and acceptable specificity of AUDIT, the test can be used as an effective instrument for identification of alcohol use disorders in the Persian psychiatric out-patient population. Furthermore, the receiver operating curve found in this study resembles that found in previous studies despite the differences in alcohol cultures between Iran and countries with higher alcohol consumption.