An outbreak of Norovirus was first detected among employees of a car dealership in New York state. A catered banquet boxed meal that was prepared in Ohio and distributed to 52 car dealerships was eventually implicated in what was discovered to be a multistate outbreak. DNA analysis of sixteen norovirus isolates obtained from 16 stool samples showed an identical strain of norovirus. Illness was significantly associated with the consumption of any of four side salads served in the boxed banquet. The salads had been prepared with extensive bare hand contact. Two food workers had elevated blood titers to Norovirus; it seemed likely that a food worker had contaminated the salads.