Objective: The objective of this study was to systematically review the findings of researches on the prevalence and patterns of drug use among students. Method: The reviewed documents included scientific papers published in indexed journals as well as internal non-indexed journals, theses, presentations in seminars and reports released by researchers and organizations. Findings of studies about three indicators including “lifetime use”, “current use” and “daily abuse” on opium, alcohol, cannabis, cocaine, hallucinogens, ecstasy and steroids have been presented in this paper. Findings: This review shows that almost all studies have been conducted after the year 1999. Many studies have methodological problems that limit their utility. Nevertheless it can be concluded that alcohol followed by opium and cannabis are the most common illegal drugs used by this population. In Iran, the number of students that are dependent to opium estimated to be between 6000 to 10000. Result: Conducting national good quality studies as well as developing an accurate monitoring system for assessing changes in prevalence and patterns of drug use in students are recommended.