Background & Aim: Identifying the mental disorders is the one of the factors that can help health care providers to recognize the addict persons who have higher possibility of relapse and guide them to planning for helping to high risk people. The purpose of this study was to determine the prevalence of psychiatric disorders and its related factors in addicted persons refereed to substances withdrawal centers.

Material & Method: This study is a cross-sectional study. 150 clients who refereed to Dezful withdrawal addiction centers,enrolled randomly with classified (by the allocation ratio) method. After completing Informed consent, participants completed SCL-90 and demographic questionnaire. The data was analyzed by Spearman, Pearson, MANOVA, DUNCAN tests with use software SPSS(version 15).

Results: 123 of participants had mental disorders. The most common substance used was opium and the most common of mental disorders was depression. There were significant relationship between psychiatric disorders and age (0.006) and the type of substance (0.001)But there were no statistically significant relationship between psychiatric disorders and duration of substance use (0.6) and education (0.13).

Conclusion: The results show that prevalence of psychiatric disorders among drug abusers is high . These problems more seen in lower age and Methamphetamine abusers.