This study investigates the moderating effect of parental monitoring on the relationship between flow experience and problematic game use of upper elementary school students. Control impairment and excessive playing are focused on as main symptoms of problematic game use. The data of 21,021 upper elementary school game users from the ‘2021 Comprehensive Survey on Game Excessive Immersion’ published by the Korea Creative Content Agency (KOCCA) was used for the analysis. Pearson correlation analysis was performed, and PROCESS macro was used to assess the moderating effects. Flow experience in gaming was positively correlated with control impairment and excessive playing. Parental monitoring was negatively correlated with flow experience in gaming, control impairment, and excessive playing. Parental monitoring moderates the relationship between the flow experience in gaming and the main symptoms of problematic game use (control impairment and excessive playing). These results show that the flow experience in gaming can affect the problematic game use of upper elementary school students. This study suggests that parental monitoring, a healthy parenting behavior, can be a protective factor for game use problems.