Internet surveys are popular ways of conducting surveys, and yet they raise many challenges for educational researchers. This chapter sets out what those challenges are and how to address them. Included here are: advantages and disadvantages of Internet surveys, how to construct and conduct Internet surveys, ethics, sampling and response rates. On the one hand, Internet surveys have the attractions of, for example, cost, access, speed, volume of data, convenience, attractiveness, ease of completion and response checking, and anonymity. On the other hand, they pose problems of privacy, confidentiality security, sampling, dropout, Internet connectivity, layout variation, response rates, misreporting and satisficing. The chapter indicates how to address such issues. It also notes that Internet-based surveys are changing rapidly, with advances in electronic devices, and that attention must be paid to smartphone and mobile phone optimization, integration of devices, formats and compatibility, security and privacy.