SUMMARYInternet gaming disorder (IGD) is a condition in which the individual is preoccupied with playing online video games and unable to regulate this behaviour, resulting in adverse physical and psychological consequences. Although there is some debate about whether IGD is an addiction or a coping mechanism, global evidence indicates that the condition is increasing in prevalence with recent advances in technology and its higher penetration into routine life. Male children and adolescents located in East Asian countries are at higher risk than others in the world. Attention-deficit hyperactivity disorder, depression and anxiety are typically associated with IGD. Given the continuing ambiguity regarding the diagnosis and screening tools for the disorder, it has become all the more relevant for mental health practitioners and academics to attend to this condition and develop evidence-based treatments. This review summarises both the existing evidence for the disorder and the debates that surround it.