Adolescence involves heightened experimentation in risk-taking behaviours that are potentially health damaging. To prevent the negative consequences of increased engagement in risk-taking behaviours, it is necessary to understand the factors that influence adolescents' participation. This study investigated the extent to which late adolescents' sex, risk judgments, self-efficacy for sexual behaviour and substance use, and sensation seeking predict likelihood to engage in risk-taking behaviour. Questionnaires were administered to 46 male and 43 female University of Canterbury students aged between 18 and 20 years. Results indicated that adolescent males have significantly lower perceptions of risk than females. However, there was a tendency for over-estimation of risk. There was the predicted negative relationship between risk perception and likelihood to engage in risk-taking behaviours. Stepwise regression analyses indicated that sensation seeking was the main predictor of risk-taking likelihood, accounting for 36.8% of the variance. The inclusion of risk perception explained an additional 4.7% of the variance. Lower self-efficacy was also significantly related to higher risk-taking likelihood. Implications for adolescent risk intervention and education programmes will be discussed.