Objective. In the third quarter of 2001, the National Immunization Survey (NIS) began collecting data on the initiation and duration of breastfeeding and whet her it was the exclusive method of infant feeding. Using the data from the 2002 NIS, this study estimates breastfeeding rates in the United States by characteristics of the child, mother, or family. Methods. The NIS uses random-digit dialing to survey households nationwide with children 19 to 35 months old about vaccinations and then validates the information through a mail survey of the health care providers who gave the vaccinations. In 2002, ～3500 households from the NIS were randomized to 1 of the 3 rotating topical modules that covered breastfeeding. Results. More than two thirds (71.4%) of the children had ever been breastfed. At 3 months, 42.5%of infants were exclusively breastfed, and 51.5%were breastfed to some extent. At 6 months, these rates dropped to 13.3%and 35.1%, respectively. At 1 year, 16.1%of infants were receiving some breast milk. Non-Hispanic black children had the lowest breastfeeding rates. Breastfeeding rates also varied by participation in day care or the Women, Infants, and Children program, socioeconomic status, and geographic area of residence. Conclusions. Although the rate of breastfeeding initiation in the United States is near the national goal of 75%, at 6 and 12 months postpartum the rates of breastfeeding duration are still considerably below the national goals of 50%and 25%, respectively. In addition, rates of exclusive breastfeeding are low. Strenuous public health efforts are needed to improve breastfeeding behaviors, particularly among non-Hispanic black women and socioeconomically disadvantaged groups. In the third quarter of 2001, the National Immunization Survey (NIS) began collecting data on the initiation and duration of breastfeeding and whet her it was the exclusive method of infant feeding. Using the data from the 2002 NIS, this study estimates breastfeeding rates in the United States by characteristics of the child, mother, or family. Methods. The NIS uses random-digit dialing to survey households nationwide with children 19 to 35 months old about vaccinations and then validates the information through a mail survey of the health care providers who gave the vaccinations. In 2002, ~ 3500 households from the NIS were randomized to 1 of the 3 rotating topical modules that covered breastfeeding. Results. More than two thirds (71.4%) of the children had ever breastfed. At 3 months, 42.5% of infants were exclusively breastfed, and 51.5% were breastfed to some extent. At 6 months, these rates were dropped to 13.3% and 35.1%, respectively. At 1 year, 16.1% of infants were rec Non-Hispanic black children had the lowest breastfeeding rates. Breastfeeding rates also varied by participation in day care or the Women, Infants, and Children program, socioeconomic status, and geographic area of ​​residence. Conclusions. Although the rate of breastfeeding initiation in the United States is near the national goal of 75% at at 6 and 12 months postpartum the rates of breastfeeding duration are still quite below the national goals of 50% and 25% respectively. In addition, rates of exclusive breastfeeding are low. Strenuous public health efforts are needed to improve breastfeeding behaviors, particularly among non-Hispanic black women and socioeconomically disadvantaged groups.