CDC's National Immunization Survey (NIS) provides ongoing national estimates of vaccination coverage among children aged 19-35 months, based on the data for the most recent 12 months, for each of the 50 states and for 28 selected urban areas. The NIS was implemented in April 1994 to monitor vaccination coverage levels as part of the Childhood Immunization Initiative (CII), a national strategy to ensure high vaccination coverage of children during the first 2 years of life. This report presents the findings of the 1997 NIS, which indicate that vaccination coverage among U.S. children aged 19-35 months remains at the highest levels ever, but that some new vaccines or recommended vaccine doses are below 90% coverage levels.