OBJECTIVE: The goal was to determine whether disparities in childhood immunization coverage exist between American Indian/Alaska Native children and non-Hispanic white children. METHODS: We compared immunization coverage with the 4 diphtheria-tetanus-pertussis, 3 poliovirus, 1 measles-mumps-rubella, 3 Haemophilus influenza type b, and 3 hepatitis B(4:3:1:3:3) series and its individual vaccine components (> or = 4 doses of diphtheria, tetanus, and pertussis vaccine; > or = 3 doses of oral or inactivated polio vaccine; > or = 1 dose of measles, mumps, and rubella vaccine; > or = 3 doses of Haemophilus influenzae type b vaccine; and > or = 3 doses of hepatitis B vaccine) between American Indian/Alaska Native children and non-Hispanic white children from 2000 to 2005, using data from the National Immunization Survey. RESULTS: Although immunization coverage increased for both populations from 2001 to 2004, American Indian/Alaska Native children had significantly lower immunization coverage, compared with non-Hispanic white children, over that time period. In 2005, coverage continued to increase for American Indian/Alaska Native children but decreased for non-Hispanic white children, and no statistically significant disparity in 4:3:1:3:3 coverage was evident in that year. CONCLUSIONS: Disparities in immunization coverage for American Indian/Alaska Native children have been present, but unrecognized, since 2001. The absence of a disparity in coverage in 2005 is encouraging but is tempered by the fact that coverage for non-Hispanic white children decreased in that year.