Introduction Adolescents sleep shows marked variation in duration and variability (Carskadon, 1982, Dahl e Lewin, 2002, Fredriksen et al., 2004); this is caused by the specific maturation period of adolescence and by external factors, among which the increasing school demands, high tech gadgets, the need of social interactions and health related factors must be accounted for. Furthermore, due to specific maturation characteristics the adolescent brain remains more vulnerable to impulsive behaviors in sex, food and sleep habits (Arain et al. 2013). Objectives To evaluate the impact of sleep deprivation (SD) upon current risk behaviors of adolescents, namely those involving reduced impulsive control. Materials and methods The Portuguese survey reported in this study is a component of the Health Behaviour in School-Aged Children (HBSC) study (Currie, Roberts, & Morgan, 2004; Matos et al., 2006). This survey is based on a self-completed questionnaire to be administered in schools by teachers. The Portuguese HBSC survey included pupils in the 8th and 10th grades (high school); the mean age was 14.91 years (SD = 1.255, min 12.5, max 19.0). The National sample consisted of 3476 students from randomly chosen Portuguese schools, representing those school grades in the entire country, as geographically stratified by Education Regional Divisions. The school response rate was 89.9%. The gender and grade distribution were as follows: 53.8 % (n = 1869) were girls; in terms of school grade they were distributed as follows: 45.9% (n = 1594) attending the 8th grade, 54.1% (n = 1882) the 10th grade. This study used a Health Behaviour in School-Aged Children (HBSC 2010) questionnaire and inquired about: (1) gender and age; (2) socio demographics and self-reported BMI; (3) Family environment (social level, instruction level and employment of father and mother); (4) Sleep duration during the week and weekends, sleep deprivation; (5) Overnight dating in friends; (6) Risk behaviours: bullying, use of weapons, non-suicidal self harm, alcohol and drugs. Results In what concerns risk behaviours it is clear from table 6 that their prevalence is relatively high in what concerns chronic use of alcoholic beverages (13.6%) and getting drunk (8.0%), use of soft drugs (11.4%) and drugs themselves (7.3%). All these behaviours are more prevalent in the sleep deprived adolescents with high significance levels (χ2 = 60.047; p = .000; χ2 = 62.116; p = .000; χ2 = 42.053; p = .000; χ2 = 25.878; p = .000; respectively). In what concerns social behaviors dating with friends, which implies returning home during the morning at 6 or 8 am., is also quite frequent routinely done by students during every weekend or even more (25.3%). The prevalence significantly increases in SD adolescents (χ2 = 43.363; p = .000). Aggressive behaviors such as carrying weapons to school (6.7%) or being involved in fights (19.6) are also relatively frequent and the prevalence increases in SD adolescents (χ2 = 14.484; p = .006 and χ2 = 14.331; p = .006, respectively) Auto aggression, namely self cutting, had a prevalence of 15.5%, and is also significantly associated with SD (χ2 = 11.055; p = .026). Suffering (9.8%) or being involved in provocations or bullying (12.2%) are not so frequent and are also not related with SD. Conclusion Most risk behaviors are strongly correlated with SD, namely consumption of alcohol and drugs, aggressive and violent behaviors and self cutting. No correlation was found with bullying and provocative behaviour. The impact of SD upon emotional and impulsive control in adolescents and young adults requires proper and detailed evaluation. Acknowledgements Aventura Social team regarding data collection and Ministry of health (grant).