Parental mediation to protect children from gaming disorders may have unintended consequences. According to the self-determination theory, parental mediation with psychological control may exacerbate problem behavior. Therefore, investigating the indirect effects of parental controlling mediation on gaming disorders is worthwhile. This study aimed to examine the conditional effect of parental controlling mediation on the relationship between escape motivation and gaming disorder, mediated by daily game time. The following research questions were investigated: whether escape motivation has an indirect effect on gaming disorder through daily game time, and whether parental controlling mediation moderates the relationship between gaming disorder and daily gaming time. The convenience sample included 501 mid-school students (251 male and 250 female) in grades 5–7. The conditional indirect effects model was developed using Hayes’s model 14 and Process Macro. The results showed that escape motivation was positively related to gaming disorder through daily game time, and parental controlling mediation had a moderating effect on the relationship between daily game time and gaming disorder. These findings suggest that parental mediation to protect children from excessive gaming may be related to gaming disorder when implemented with psychological control. Higher parental controlling mediation may be a risk factor for gaming disorder even when their children play games less frequently. These findings are discussed in light of the literature.