Background: Cartoon violence causes significant changes on the behavior of children especially among primary school children such as aggressive behavior. Aim: Aim of this study was to assess the relationship between cartoon violence and aggressive behavior among primary school children. Research design: A descriptive design was utilized in this study. Setting: This study was conducted at selected primary governmental schools in Benha city at Qaliubiya Government. Sample: A multistagerandom sample from (400) children was taken from the previously mentioned setting by taken randomly one grade from selected school then taken all children from these grades. Tools: (I): A structured interviewing questionnaire sheet, (II): Attitude scale for children toward cartoon violence, (III): Aggression scale for children. Results: More than three quarters of the studied primary school children's had a positive attitude toward cartoon violence and more than half of them had severe level of aggression. Also, there was positive significance correlation between children's attitude toward cartoon violence and their aggressive level. Conclusion: Cartoon violence influence positively on aggressive behavior among the primary school children as There was a positive significant correlation between cartoon violence and aggressive behavior among the studied primary school children. Recommendations: Parents should put consistent limits on hours per day of cartoon watching and encourage their children to do other physical and social activity such as reading, drawing and any sports in spite of spending time on cartoons watching.