The Minnesota Department of Health foodborne illness hotline received a succession of complaints of illness from people who had recently eaten at a Hinckley, Minnesota, restaurant. A list of recent patrons was compiled by epidemiologists who then phoned the patrons to establish food histories and illness numbers. The survey found twenty eight people who fit the case definition. Stool samples from thirteen cases were positive for Norovirus; five of these isolates underwent nucleic acid sequencing and were found to be identical. Analysis of the food histories found significant risk associated with eating items in the salad bar. No specific food item from the salad bar was identified as the source of the illness. Two food workers reported illness two days before the outbreak started. They likely contaminated ready-to-eat items in the salad bar.