Background: Evidence of violent crimes due to consumption of psycho stimulants like Crystal (or Glass) was the main reason for designing the study to find the prevalence of such crimes in referred cases to Tehran branch of LMO, in 2013.

Methods: This is a cross- sectional descriptive analysis, including all cases referred by criminal courts during the study. In all cases, both criminal files and clinical records, as well results of psychologic and psychiatric examinations, along with other necessary information (e.g. type of crime committed, records of previous psychological disorders and during the criminal act, and other parameters) were gathered and studied.

Findings: The present study was carried out on 138 cases referred to LMO's Psychiatrics Department, all were male. 84 of which single and 30 divorced. The mean of age in these cases was 28.4 (SD=6.2). All of them had records of committing violent crimes including quarrel (35), theft (25) and murder (12). Nearly half of them (57) were unemployed and most of them (114) had a long history of substance abuse (psycho stimulants like Crystal or Glass).

Conclusion: The fact that the rate of committing violent crimes (e.g. quarrel, robbery, murder,…) among those who use psycho stimulants is considerably high, makes it necessary to inform the youth and families through media campaigns about the potential role of these substances in criminal behavior among users.