In April 2012 ten restaurant patrons became ill with norovirus following a meal on April 22. Nine persons from one group and one person from a second group met the case definition. The median incubation period was 41 hours (range 14, to 105 hours). The median duration of illness was 3.5 days (range, 1 to 5 days). Stool samples submitted by two ill patrons from the first group tested positive for norovirus GII. Two cases were likely secondary person-to-person transmission of norovirus. The limited number of non-ill controls precluded a meaningful statistical analysis of food exposures. Ramsey County Environmental Health sanitarians interfviewed 21 restaurant employees. One reported an onset of vomiting and diarrhea on April 23. This employee worked as a cashier and server on April 22 but could not recall if he prepared foods. Public health investigators concluded this was an outbreak of norovirus associated with a restaurant in Roseville, Minnesota. No vehicle was identified. The source of transmission was not identified.