In March 2002 the Los Angeles County Department of Health Services (LAC DHS) investigated an outbreak of norovirus infections among attendees of an Academy Awards Banquet held at the Regent Beverly Wilshire Hotel. Both attendees and hotel workers were interviewed. Approximately 560 persons attended the banquet. One hundred eighty four were interviewed. Eighty five persons met the case definition. No one was hospitalized and no one died. Six of 16 stool specimens collected from attendees were positive for norovirus and 2 of 29 hotel employee specimens were positive for norovirus. Employees who submitted positive stool specimens were not involved in food preparation. They became ill after the banquet. Investigators did not determine the vehicle for patron and staff illnesses.