The internet is one of a range of health information sources available to adolescents. It is recognised that young people have difficulties accessing traditional health services; in theory, the internet offers them confidential and convenient access to an unprecedented level of information about a diverse range of subjects. This could redress adolescents' state of relative health 'information poverty', compared to adults. This paper seeks to explore United Kingdom (UK) and United States (US) adolescents' perceptions and experiences of using the internet to find information about health and medicines, in the context of the other health information sources that are available to them. The study involved a series of 26 single-gender focus groups with 157 English-speaking students aged 11-19 years from the UK and the US. Many students reported that the internet was their primary general information source. Information sources were defined during analysis in terms of previous experience of the source, saliency of the available information, and credibility of the source (defined in terms of expertise, trustworthiness and empathy). Most focus group participants had extensive personal experience with the internet and some information providers therein (notably search engines). Internet health information was regarded generally as salient. Its saliency was increased through active searching and personalisation. Perceived credibility of the internet varied because expertise and trustworthiness were sometimes difficult to determine, and empathy could be facilitated through online communities but the individual could control disclosure. The internet combines positive features of traditional lay and professional, personal and impersonal sources. Although it is unlikely to supplant the role of trusted peers and adults, the internet has found an important place among adolescents' repertory of health information sources.