Background: Since electronic gaming is particularly appealing to children and adolescents, they may be at greater risk for developing Internet Gaming Disorder (IGD). This study aimed to explore the characteristics of adolescents at risk of developing IGD because it is a relatively new disorder included in Diagnostic and Statistical Manual of Mental Disorders in 2013. Harmful consequences of disordered gaming have also been recognized by the World Health Organization that recently included ‘Gaming Disorder’ in the eleventh revision of the International Classification of Diseases. Additionally, this study also sought to encourage preventative initiatives in adolescence, when most addictions develop. Methods: A quantitative and nationally representative study was conducted in primary schools in Slovenia with eighth grade as the primary sampling unit (N = 1,071, Meanage = 13,44 years, SDage = 0.59). Psychometric test measuring IGD was administered to identify participants’ IGD risk and to compare ‘high risk’ and ‘low risk’ students in relation to free time activities, self-control, and parent-child relationship. T–test for independent samples was computed and multiple linear regression analysis performed to identify the most relevant predictors of IGD.Results: About 4.7% (n = 48) [95% CI: 3.4%-6.0%] of Slovenian adolescents were found to be at high risk of developing IGD. These were mostly boys (n = 42, 87.5%), and their preferred leisure activities involved more screen time activities (e.g., watching TV, playing video games, using social media). Moreover, high risk IGD participants showed significantly lower levels of self-control compared to low risk IGD participants and poorer understanding with their parents. Perceived satisfaction with life and mental health did not differ significantly between the two groups. Multiple linear regression analysis revealed five key predictors of IGD in adolescents: time spent gaming at weekends (ß = 0.27), male gender (ß = 0.20), low self-control (ß = -0.19), time spend gaming from Monday to Friday (ß = 0.11) and gaming as a frequent free time activity (ß = 0.11).Conclusion: Public health measures should target adolescents at risk of developing IGD in early age, because they are particularly drawn to video games and present greater IGD vulnerability.