Background: One of the most exciting fields of mankind life in the recent century is computer–video games that have an increasing popularity among children and adolescents. However, it has incited the general anxiety from the probable destructive effects on these age groups. One of the major concerns is the obvious feature of aggressiveness. The present study was designed to survey the association between computer–video games and aggression in male students of guidance schools in Tehran.Materials and methods: The study population included 333 male students of guidance school who have been randomly selected. They were requested to fill both the research and aggression questionnaires.Results: Results have revealed a non-significant direct association between aggression and computer video games. However, there was a significant relationship between the time of proceeding to these games and type of game with the types of aggression in a way that increasing the rate of proceeding to these games and harsh games, the rate of student’s aggression was increased.Conclusion: Our results showed that encountering to the computer games continually may cause the manners of aggression and decreasing of educational function.