Affective influences may play a key role in adolescent risk taking, but have rarely been studied. Using an audiovisual method of affect induction, two experimental studies examined the effect of positive affect on risk perceptions in adolescence and young adulthood. Outcomes were risk perceptions regarding drinking alcohol, smoking a cigarette, riding in a car with a drunk driver, getting into a fight, and having unprotected sexual intercourse. Study 1 showed that positive affect led to lower risk perceptions than neutral affect for young adults (mean age 23). Study 2 replicated the effect for early adolescents (mean age 13), mid-adolescents (mean age 17), and young adults (mean age 23). Moreover, Study 2 showed that the effect was most pronounced at high levels of impulsiveness. Adolescents and young adults may be more risk averse in contexts that do not give rise to emotions, but have markedly lower risk perceptions under positive affect. (Contains 3 figures.)