The present study aimed to investigate the current situation of internet gaming disorder (IGD) in Chinese adolescents and explore the impact of IGD-related factors on adolescent aggression. We hypothesized that IGD symptoms in adolescents would be associated with aggressive behavior and that risk factors for IGD symptoms could increase the aggressive tendencies of adolescents. To verify the above hypothesis, a cross-sectional survey of junior and senior high school students from southern, southwestern, central, and eastern China was conducted. A total of 9306 valid questionnaires were collected. The results showed that the prevalence of IGD symptoms was 1.78 % among Chinese adolescents. The adolescents in the disordered gamer group had the most severe IGD symptoms, with the highest levels of psychological distress and aggression. Interestingly, adolescents in the casual gamer group had the lowest psychological distress and aggression scores. Linear regression analysis further showed that higher levels of aggression were significantly associated with male sex, younger age, more severe psychological distress and IGD symptoms, and more violent game exposure. Our results suggested that excessive online gaming not only contributes to psychological distress in adolescents but also increases their levels of aggressive behavior. Apart from male sex and younger age, severe IGD symptoms and psychological distress are the most important predictors of the development of aggressive behavior.