Vaccination is the most effective way to prevent influenza-associated morbidity and mortality. However, influenza vaccination coverage among children historically has been low. The Advisory Committee on Immunization Practices (ACIP) recommends annual vaccination with influenza vaccine for all children aged 6-59 months. Previously unvaccinated children and children who received only 1 vaccine dose for the first time in the previous influenza season are recommended to receive 2 influenza vaccine doses. To assess vaccination coverage among children aged 6-59 months during the 2007-08 influenza season, CDC analyzed data from the eight immunization information system (IIS) sentinel sites. For the eight sites, an average (unweighted) of 40.8% of children aged 6-23 months received 1 or more influenza vaccine doses, and an average of 22.1% were fully vaccinated. Among children aged 24-59 months, an average of 22.2% received 1 or more doses, and an average of 16.5% were fully vaccinated. These results indicate that influenza vaccination coverage among children remains low and highlight the need to identify additional barriers to influenza vaccination and to develop more effective interventions to promote vaccination of children aged 6--59 months who are at high risk for influenza-related morbidity and mortality.