The Internet offers water professionals widespread opportunitites to disseminate and obtain water quality data. As part of a US Environmental Protection Agency pilot project, the Des Moines (Iowa) Water Works is posting its finished water quality data in real time on the World Wide Web. Some utilities have also instituted Web sites; others are still in the process of determining the type and extent of information to post on the Internet. This article cautions water professionals about the pitfalls associated with cyberspace data - notably inaccuracy and inaccessibility - and briefly describes the major sites providing water quality information.