AbstractBackgroundAlthough the use of the Web has brought major advances in every step of the research process, this also comes with several methodological challenges.AimThe article presents the European Society for Sexual Medicine's position statements on key methodological concerns relative to Web-based research in sexual medicine.MethodsThe authors conducted a systematic scoping review of articles using Web-based research methods in sexual medicine. For the creation of the statements, the authors processed the data from the methodology of the studies and formulated the final statements reaching 100% agreement in the group.OutcomesEuropean Society for Sexual Medicine statements were provided on the following domains: definition of the population of interest, selection of the population of interest, data collection quality, response rate, self-reported questionnaire, consent, and legal obligations.ResultsResearchers should justify the relevance of the Internet population to the population of interest; should clearly describe how they identified study participants; should select and employ specific measures to avoid hoax; should explicitly describe the process of calculation of response and completion rates as well as the relative implications; should validate traditional sexual health questionnaires for online and, if possible, multilingual use; should not ignore consent in Web-based research; and need to be knowledgeable of the technical measures and legal obligations to protect anonymity.ImplicationsResearchers are advised to include trained computer scientists in their group, have a good understanding of their legal obligations as to collecting, storing and disseminating personal data, and design their studies by taking into account the challenges of Web-based research.Strengths and limitationsThe heterogeneity of the included studies and methodological low quality of most of them was a limitation, which also shows the importance of this study and the need for guidelines regarding Web-based research.ConclusionLarge uncontrolled samples could be a threat to the quality of the studies and increase bias if researchers are not mindful of the methodological challenges they would need to account for.