A limited number of studies suggest that about half of patients for whom influenza vaccine is indicated (based on age or other high risk conditions) who have not yet received influenza vaccination during the current season would accept vaccination if it was offered to them during an ED visit. However, since these studies were conducted early in the vaccination season and involved the use of convenience samples, the results might not be generalizable to all patients seen in an ED throughout the vaccination season. The proportion of persons who would not have been vaccinated elsewhere but would accept vaccination in EDs has not been demonstrated. Therefore, the true potential of vaccination in EDs to increase vaccination coverage is unknown.