Problem Statement: Cell phones are among the most popular technologies whit various applications. Despite their advantages, they leave some disadvantages on behaviour. This study surveys the harmful effect of cell phones on aggression. Samples were chosen randomly from among the high school students of Malayer, Iran. Samples were 180 students (90 males and 90 females). They completed aggression questionnaire (AQ) with an Alpha score ranging between 0/72 - 0/80 for reliability. Its validity was certified by the experts. In conclusions the study reveals that using cell phones makes students relationship more aggressive significantly in 2 scales of AQ (anger and physiologic aggression), but not in verbal aggression and hating (the other 2 scales of AQ). Therefore, we recommend cell phones to be used just in necessity. Due to the harmful effects, Parents are not recommended provide their young children with cell phone. There is a necessity for more research in this ground.
