Sudden infant death syndrome (SIDS) is one of the leading causes of postneonatal mortality in the United States. To reduce the risk for SIDS, the American Academy of Pediatrics (AAP) recommends that all healthy babies be placed to sleep on their backs. In 1994, a national "Back-to-Sleep" education campaign was begun to encourage health-care providers and the public to adopt a back or side sleeping position for all infants. To assess the response to these recommendations, CDC analyzed population-based data on infant sleeping positions during 1996 and 1997 from 13 states participating in the Pregnancy Risk Assessment Monitoring System (PRAMS). This report summarizes the results of that analysis and indicates that from 1996 to 1997 placement of infants in the stomach sleeping position declined significantly in four states and placement of infants in the back sleeping position increased significantly in nine states. However, the percentage of infants placed on their stomachs continued to differ by state, maternal demographics, and type of insurance coverage.