Pathological gambling can be a serious problem, more so to a vulnerable population such as adolescents and youth. This study aims to investigate the links between gambling behaviours and impulsivity through a multidimensional approach in a French adolescent population. A secondary aim of this study is to find out the prevalence of pathological gambling behaviour amongst adolescents who are not meant to have legal access to such games. We administered the UPPS Impulsive behaviour Scale (UPPS-P) and the Canadian Pathological Gambling Index CPGI to 1800 adolescents aged between 11 to 17 years. Our results indicate that 33% of subjects have gambled at least once during the last year and that girls gamble as much as boys (17% and 16% respectively). Scratch games are the most common games played by adolescents (81.4%). We also notice that 1.6% of our population has problematic gambling behaviour. Although we found that many dimensions of impulsivity (Urgency, Positive urgency and Sensation seeking) are correlated to gambling behaviour, only sensation seeking seems to be a good predictor of pathological gambling severity. These results can be taken into account in the development of prevention programs.