This article discusses ethical and quality issues involved in accessing and evaluating Internet-based information on alcohol, tobacco, and other drugs (ATODs). After a brief overview of the World Wide Web and its potential for increasing knowledge in the fields of ATOD prevention, treatment, research, and policy, we discuss potential threats that may compromise the quality and utilization of Web-based ATOD information. Consumers and authors of Web-based materials must critically assess and evaluate that information; the Information Quality Tool developed by the Health Summit Working Group is suggested as an analytic framework useful in evaluating ATOD information. The article concludes with observations about future issues regarding dissemination of ATOD information on the Internet.