Background and aims: Although sedentary behaviours are linked with mortality for cardiovascular reasons, it is not clear whether they are negatively related with cardiometabolic risk factors. The aim was to examine the association between time engaged in television ( TV) viewing or playing with videogames and a clustered cardio-metabolic risk in adolescents. Methods and results: Sedentary behaviours and physical activity were assessed in 769 adolescents (376 boys, aged 12.5-17.5 years) from the HELENA-CSS study. We measured systolic blood pressure, HOMA index, triglycerides, TC/HDL-c, VO(2)max and the sum of four skinfolds, and a clustered metabolic risk index was computed. A multilevel regression model (by Poisson) was performed to calculate the prevalence ratio of having a clustered metabolic risk. In boys, playing >4 h/day with videogames (weekend) and moderate to vigorous PA (MVPA) was associated with cardio-metabolic risk after adjustment for age, maternal education and MVPA. In contrast, TV viewing was not associated with the presence of cardio-metabolic risk. Conclusion: In boys, playing with videogames may impair cardio-metabolic health during the adolescence. Adolescents should be encouraged to increase their participation in physical activity of at least moderate intensity to obtain a more favourable risk factor profile. (C) 2012 Elsevier B.V. All rights reserved.