While the influences of the Internet on adult sexuality are well recognized, research on the potential connection between the Internet and young people's sexuality is still limited. We conducted a qualitative study to examine how young people (aged 15-19 years) in Hanoi, Vietnam used the Internet to develop sexual practices and identities. Our analysis of texts from focus groups, in-depth interviews, chat scripts and field notes reveals how the Internet is used to assemble sexual information that was not available from other sources such as the family and school. Young people's narratives also show how they use the Internet as a medium for expressing sexual identities and desires. In the light of these findings, we suggest expanding sex education to include issues that are important to young people such as emotions and relationships, rather than simply focusing more narrowly on reproduction, public health and other interests of the state.