Infants and children aged <2 years often require medical care for influenza and have higher rates of influenza-related hospitalization than any other age group except persons aged >or=65 years. Since 2004, the Advisory Committee on Immunization Practices (ACIP) has recommended seasonal influenza vaccination for all children aged 6-23 months. Full vaccination for these children requires receipt of 2 doses in the current influenza season if they have not been vaccinated previously or received a single dose during the preceding season. To assess influenza vaccination coverage among children aged 6-23 months during September-December of the 2007-08 influenza season, CDC analyzed data from the 2008 National Immunization Survey (NIS). The results of those analyses indicated that, during the 4 months, 40.7% of children aged 6-23 months received >or=1 doses of influenza vaccine, and 23.4% were fully vaccinated. Substantial variability was observed among the 50 states and participating local areas; the percentage of children with full vaccination ranged from 6.4% to 40.9% among states and local areas. Nationally, the percentage of children aged 6-23 months receiving >or=1 doses of influenza vaccine increased from 31.8% in 2006-07 to 40.7% in 2007-08, and the percentage with full vaccination increased from 21.3% to 23.4%; however, influenza vaccination coverage among children remains low. Further study is needed to identify barriers to influenza vaccination and to implement strategies that can increase vaccination coverage with emphasis on attaining full vaccination in this population at greater risk for complications from influenza.