Abstract Background STI surveillance systems are subject to qualitative and quantitative underreporting. General practitioners (GPs), who are key subjects in case reporting, explain their underreporting partly by their observation that taking a sexual history is embarrassing for patients, and that patients are reluctant to disclose information on their sexual practices. In this study we examine patients' willingness to provide data for STI surveillance. Methods A questionnaire-based survey in a stratified population sample of 300 patients aged 18–60 years. Results The large majority of respondents stated to be willing to give information on their sexual practices for the purpose of STI surveillance. They preferred to answer sexual history questions to their GP; filling in a form on the internet was the second best option. Conclusion Based on these results, it is unlikely that the cooperation of patients would be a weak link in STI surveillance strategies. This observation, together with the fact that the ...