Three patrons of an Olmsted County, Minnesota, restaurant reported illness to the local health department on March 1. The party had eaten at the restaurant on February 27, and subsequently suffered gastrointestinal illness. On March 5, a fourth case was reported. This prompted an outbreak investigation. The restaurant was inspected and it was discovered that two employees had recently been ill with gastrointestinal illnesses. Stool samples from the ill patrons and one employee were analyzed. The four patrons' samples contained the same strain of Norovirus, but the employee's sample did not contain Norovirus. The health department concluded the outbreak was caused by ill employees handling ready-to-eat foods.