BACKGROUND: Having been vaccinated against the human papilloma virus (HPV) may affect other behaviours related to sexual health. This study assessed knowledge and behaviour relevant to the prevention of sexually transmitted infections (STIs) among girls/women aged 14-23 years in relation to their HPV vaccination status. METHODS: From November 2008 to February 2009, 328 girls/women from the Rhône-Alpes region were recruited by general practitioners and completed a self-administered questionnaire. RESULTS: In all, 316 of the 328 respondents provided information on their HPV vaccination status: 135 (42.7%) had been vaccinated (51.2% of girls aged 14-16 years, 44% of women aged 17-20 years and 18.9% of 21-23-year-olds). Knowledge about HPV and the Pap smear was poor overall but greater in those who had been vaccinated: vaccinated 14-16-year-olds were significantly more likely to know the aim of the Pap smear than those not vaccinated (72.7% vs. 41.3%, P < 0.001), and vaccinated 21-23-year-olds were more likely to know about the need to continue Pap smear screening, despite vaccination (60.0% vs. 25.6%, P = 0.06). Irrespective of vaccination status, >80% cited condoms as a means of STI prevention and >85% of those who were sexually active used them. No difference was observed between vaccinated and non-vaccinated groups regarding requests for HIV serology, history of abortions or emergency hormonal contraception. CONCLUSION: Knowledge about cervical cancer prevention was better among those who had been vaccinated against HPV than among those who had not. Knowledge and behaviour relevant to STI prevention seemed appropriate whatever the respondents' vaccination status.