A wedding party in Minnesota reported gastrointestinal illnesses after eating at a Pequot Lakes restaurant on February 28, 2004. The health department also received reports of illnesses from other retaurant patrons and from the restaurant. The health department investigation began by contacting diners and gathering illness status and food histories. Stool samples were collected and tested positive for Norovirus. A case-control study of the food histories found that consumption of baked potatoes and salads with French dressing were associated with an increased risk of illness. An inspection of the restaurant discovered bare hand contact with ready-to-eat foods and recently ill employees. One employee submitted a stool sample that contained Norovirus that matched genetically with the strain found in ill restaurant patrons.