Objective. Few social scientists have examined how Internet usage, including using the Internet for health purposes, may affect mental health. This study assesses whether the type or amount of online health activities and the timing of Internet use are associated with psychological distress. Methods. We use data from the National Cancer Institute's 2005 Health Information National Trends Survey. Results. When we compare Internet users to non-Internet users, using the Internet and using the Internet for health purposes are negatively associated with distress. However, among Internet users, the number of online health activities is positively associated with distress. Greater distress is also associated with using the Internet on weekdays and looking online for information on sun protection. Conclusions. Internet usage is not necessarily positively associated with psychological distress. The effects depend on the type, amount, and timing of Internet usage. © 2011 by the Southwestern Social Science Association.