In this study we investigated the prevalence of sexual aggression as reported by adolescent males and females in the Netherlands. Data were collected from a low-risk school-based sample (n= 219; 119 adolescent females and 100 adolescent males), a medium-risk school-based sample (vocational training) (n=237; 117 adolescent females and 120 adolescent males); and a high-risk sample from eight different juvenile justice institutions (n=377; 215 adolescent females and 162 adolescent males). Participants reported on the strategy used to force a person into sexual contact (defined as sexual touching, sexual intercourse or oral sex) against his/her will. Results showed that around 8% of the adolescent females and 10% of the adolescent males reported having used sexual aggression against a person. However, prevalence rates differed for the different samples: the juvenile institution sample showed the highest rate. Further, we found that for adolescent females "beliefs about sexual behaviour" was the only predictor of sexually aggressive behaviour, while for adolescent males being a victim of sexual abuse was the most important predictor. The results are discussed in relation to the literature on sexually aggressive offending behaviour. © 2011 National Organisation for the Treatment of Abusers.