This article reports on a study of how teenagers made their decision on whether or not to vaccinate themselves against the new influenza. Its purpose was to identify connections between how teenagers talk about themselves and the decision they made. How do the teenagers construct their identities while talking about a specific socio-scientific issue? Seven teenagers between 17 and 19 years of age participated in the study. The informants were requested to document in video diary situations in which their decisions about the vaccination were discussed. All the teenagers recorded their diaries during the weeks of the vaccination programme. The students were also interviewed 1-4 weeks after completing their diaries. A discourse psychology framework (Potter and Wetherell "1987") was used to analyse the video diaries and the interviews. In this context, decision-making on a socioscientific issue must be understood as an appropriation and use of discursive repertoires, and also as meaning-making in relation to other fields, such as society and identity. It must also be understood in relation to the use of science repertoire--or actually, the school science repertoire--how available is this discourse in different contexts outside school? The repertoires were categorised into two main types; experienced emphases and important actors. The first included the categories of risk, solidarity and knowledge. The second included family and friends, media, school and society. The school repertoire was seldom used by the students, indicating that school and science education seem not to be an interpretative repertoire available to them. Instead, the risk, solidarity, family and friends and the media repertoires were available in their talk about vaccination. These results indicate the need to use media reports in dealing with scientific literacy and also in risk assessment discussions in school. It also indicates the importance of relating school science closely to the students' daily life.