Foodborne illnesses are a substantial health burden in the United States. The Foodborne Diseases Active Surveillance Network (FoodNet) of CDC's Emerging Infections Program collects data from 10 U.S. states regarding diseases caused by enteric pathogens transmitted commonly through food. FoodNet quantifies and monitors the incidence of these infections by conducting active, population-based surveillance for laboratory-confirmed illness. This report describes preliminary surveillance data for 2005 and compares them with baseline data from the period 1996-1998. Incidence of infections caused by Campylobacter, Listeria, Salmonella, Shiga toxin-producing Escherichia coli O157 (STEC O157), Shigella, and Yersinia has declined, and Campylobacter and Listeria incidence are approaching levels targeted by national health objectives. However, most of those declines occurred before 2005, and Vibrio infections have increased, indicating that further measures are needed to prevent foodborne illness.