This study was conducted to investigate the psychometric properties of the Czech version of The Scale for Assessment of Pathological Computer-Gaming (AICA-S) and to identify the proportion of Internet gaming disorder (IGD) among juvenile gamblers in Czech primary schools and grammar schools. This study involves 2 475 students in age from 11 to 19 years (mean age 15 years, SD = ±2). The results of our research show that 0.8% of our respondents belong to the High risk group and 5.2% belong to the Low risk group – in both cases intervention is needed and overall prevention is recommended. We consider the most risky group to be adolescent boys attending primary schools, where up to 2.7% are in the High risk group. Factor analysis confirmed that the Czech variant of AICA-S has suitable psychometric properties (KMO = 0.94).