The frequency with which children are breast-fed is internationally recognised as an important health indicator. Breast-feeding is the natural, and often also the simplest, way to feed the baby. The close body contact associated with breast-feeding enhances the child’s feeling of safety. The composition of breast milk is exactly adapted to the nutritional needs of the child. Several studies have shown that breast-fed children run a lower risk of infection than bottle-fed children. In addition, allergies are rarer among breast-fed babies. Up until the mid-1930s, most children were born at home. As the proportion of hospital deliveries subsequently increased, the proportion of breast-fed children decreased. The decrease continued until the beginning of the 1970s, when a pronounced shift in attitudes took place, towards emphasizing the social and biological advantages of breast-feeding. This resulted in a large increase in the frequency of breast-feeding that lasted until the mid-1980s. The frequency of breast-feeding then remained constant or even decreased slightly. The period of decrease was, however, short. From the beginning of the 1990s, we have again seen a continued increase in the number of breast-fed children. The increase largely coincides with renewed efforts to support breast-feeding (the “Baby Friendly Hospitals Initiative”, BFHI), which was started on the initiative of UNICEF and which has been successfully promoted in Sweden. Support for breast-feeding from both maternal health centers and child welfare centers has also increased. The definition of breast-feeding in Sweden has been changed for infants born 2004 and onwards. This has been done to facilitates comparisons with other countries and in accordance with WHO’s definitions. This means that the category “exclusively breastfed” comprise infants who only have received breast-milk (and if needed, medication) - nothing else. Due to the change of definition it is not possible to compare the number of solely breast-fed infants born 2004 with earlier years. In an international perspective, the frequency of breast-feeding in Sweden is high. As much as 98 per cent of the children born in 2004 were breast-fed at the age of one week. More than 91 per cent were still exclusively or partially breast-fed at the age of two months. At the age of 6 months, 72 per cent were breast-fed. The rate of infants breast-fed at the age of nine months was about 42 per cent and almost 20 per cent were breast-fed at the age of twelve months. The breast-feeding rates vary widely in Sweden according to geographical region. The rate of exclusively breast-fed infants, at the age of one week, is almost 99 per cent in the county of Södermanland and 97 per cent in the counties of Kronoberg and Jämtland. At the age of sex months, 37 per cent were exclusively breast-fed in the county of Västerbotten as compared to 13 per cent in the county of Skåne. In the county of Gotland almost 25 per cent of the infants were breast-fed at the age of one year as compared to 12 per cent in the county of Halland.