This paper presents part of the results of research on the relationship between sexual behaviour and gender images among adolescents of both sexes in Argentina, with a focus on young women in the highest and lowest social classes in the greater Buenos Aires metropolitan area. The research was based on the hypothesis that gender inequality is translated into behaviour through cultural role images (gender images). This study shows that more young women from the upper-middle class have egalitarian gender images, feel more in control of their lives, tend to protect themselves during sexual relations and experience few unplanned pregnancies. Sexual and reproductive risk-taking behaviour is more likely among those who have the least educational opportunities, whose mothers had similar experiences, and among whom traditional gender concepts are maintained. The process of marginalisation of the lower class in the current economic situation will inevitably perpetuate this vicious circle. New policies and social programmes are needed, eg. so that all teenage girls can complete secondary education. Since the greatest sexual risk they face is at sexual initiation, gender-aware sexual education programmes are necessary to enable them to protect themselves.