Background and aims: Vietnam implemented numerous measures to reduce the transmission of COVID-19 among school students, including study-at-home/self-quarantine. During the study-athome period, adolescents may engage in more video gaming than usual, potentially contributing to gaming disorder. However, the regionally-representative prevalence of gaming disorder and its association with parenting practice and discipline practice have not been described. We assessed the prevalence of gaming disorder among Vietnamese adolescents during the initial 6 months of the COVID-19 pandemic and the associations between gaming disorder and parenting practice and discipline practice. Methods: We conducted a school-based, self-administered cross-sectional survey of 2,084 students in Hanoi, Vietnam (response rate 5 97.1%). The survey included standardized instruments translated from English to Vietnamese. We performed multilevel logistic regressions to assess the associations between parenting practice, discipline practice, and gaming disorder. Results: The prevalence of gaming disorder among the respondents was 11.6%. Healthy parent-child relationship was protective against gaming disorder (Adj OR 5 0.36; 95% CI 5 0.21, 0.62). Non-supervision, non-discipline, violent discipline were positively associated with gaming disorder. Discussion and Conclusions: We found associations between gaming disorder and parent-child relationship, parental supervision, and parental discipline. Future interventional studies should consider assessing the effect of fostering healthy parent-child relationships and appropriate discipline on the occurrence or prognosis of gaming disorders.  Kulcsszavak: Gaming disorder, COVID-19, parent-child relationship, parental supervision, discipline styles, school, adolescent, Vietnam