Modernization of electronic communication systems to facilitate infectious disease surveillance and outbreak investigation became a priority after the 2001 anthrax attacks. However, the extent to which communicable disease investigators are using web-based information resources, e-mail notifications, or secure information exchange systems to facilitate surveillance is unknown. To address this question, we conducted a survey in 2004 of state and local communicable disease investigators responsible for infectious disease surveillance and outbreak investigation in three states. The majority (70.7%) of the 297 respondents accessed the Internet for information regarding infectious disease surveillance and outbreaks at least weekly. Most (74%) respondents who searched for information from the Centers for Disease Control and Prevention (CDC) website reported that they found what they were looking for 75-100% of the time, compared with 54% who found the information from their state health department websites 75-100% of the time. One-third of respondents read e-mail notifications regarding outbreaks under investigation in their state less frequently than monthly; 34% of those enrolled in CDC's Epidemic Information Exchange (Epi-X) read e-mail notifications of new reports less frequently than monthly. Forty-seven (18%) respondents read ProMED-mail at least monthly, while 46% indicated they had never consulted MEDLINE/PubMed. Some progress has been made in use of the Internet to facilitate communication in infectious disease surveillance and outbreak investigation. Addressing barriers to access and usability of new information systems in conjunction with training and technical support could enhance infectious disease surveillance and timely investigation of outbreaks and bioterrorism events.