The aim of this study was to investigate the Dextromethorphan (DXM) abuse side effects. Subjects were 53 volunteers who had consumed DXM with mean age 23.4 years. The mean of side effects during first day was 12.49 and during first week was 5.57. The causes of repeated DXM abuse were psychological dependency 46.5%, recreational abuse in 32.6%. Neurological and psychological symptoms were the most common of side effects in DXM abusers.