Background and Aims: Emerging research has identified parents' psychological distress as a potential risk factor that increases adolescents' vulnerability to problematic gaming. This study attempted to address "why" from a relational perspective. We hypothesized that parents' psychological distress may link to adolescents' problematic gaming through the mediation of parent-child relationship quality, while the mediating effects of parent-child relationship quality may vary depending on adolescents' emotion regulation. Methods: We collected data from 4,835 parent-child dyads in China (parental age 5 41.45 +- 4.53 years; adolescent age 5 13.50 +- 1.00 years). Structural Equation Modeling (SEM) was utilized to analyze the relationships among the variables under study. Results: Parent-reported parental depression/anxiety was related to worse adolescent-reported parent-child relationship, which in turn related to more severe adolescent-reported problematic gaming. Moreover, the mediating effects of parent-child relationship quality were weaker when adolescents used more expressive suppression (but not cognitive reappraisal). Discussion and Conclusions: The findings of this study highlight the need to consider both parent-child relationships and adolescents? active role in their own emotion regulation in order to understand parental influence on adolescent problematic gaming.  Kulcsszavak: problematic gaming, parental depression, parental anxiety, emotion regulation, Chinese adolescents