Parents’ negative affect could lead to the deterioration of the mental state of their adolescent children. According to previous studies, children of parents who have symptoms of depression or anxiety are more likely to have mental problems. As one of the most important issues concerning adolescents with the rapid rise of screen time, the concern for pathological gaming among adolescents continues to intensify. Many studies have demonstrated the remarkable relationships between adolescents’ pathological gaming and mental factors, but seldom examined them via longitudinal analysis. With three-year data from adolescents (N = 778) and their parents (N = 685) in South Korea, this study assessed the effects of parents’ negative affect (depression and anxiety) on pathological gaming using adolescents’ mental factors (i.e., aggression, ADHD, self-control). The results showed the critical role of parents’ negative affect on their children’s mental health, which finally leads to pathological gaming among adolescents. Depressive parents increased the degree of adolescents’ aggression and ADHD, and decreased the degree of adolescents’ self-control. Anxious parents increased the degree of adolescents’ ADHD. Moreover, both adolescents’ aggression and self-control mediated the relationship between parents’ depression and adolescents’ pathological gaming. Specifically, self-control was one of the most influential factors contributing to pathological gaming among adolescents.