A conference in Nassau County experienced an outbreak of Norovirus in January. Reports of illness to the local health department prompted an investigation beginning January 30. Questionnaires were sent to conference participants to assess the extent of the outbreak and to find the source. The responses showed a large outbreak associated with the conference, but provided inconclusive data on the source. However, interviews with food service staff found many had worked while ill due to economic reasons. Anecdotes from other employees stated ill employees who did not report for work would be fired. The first ill worker presented on January 20, and this illness appeared to spread to other food workers. Conference attendees became ill after illnesses in the food workers began. The health department reinforced with conference center ownership the importance of excluding ill food handlers from work for at least 72-96 hours after the cessation of illness symptoms.