In Lima, Peru, a study was conducted that evaluated the influences on mothers' decisions regarding breastfeeding. Local views and health professional advice was ascertained. A follow-up study of a group of pregnant women was conducted to assess knowledge, attitude, and practice in regard to the early feeding of their children. The women were interviewed in their homes before delivery, as soon as possible after delivery, and twice a week until their babies were 1 month old. The experience of the mother was the key factor, but advice from relatives, neighbors, and health professionals was also important. A lack of information about exclusive breast feeding was common. Although the women knew breast feeding was good, they were unaware that exclusive breast feeding was best. Health workers knew to advise against other milks, but failed to advise mothers against the use of herbal teas and sweetened water as supplements. The women commonly believed they were unable to produce enough milk to feed their children because of their own undernourishment. Others believed exclusive breast feeding would worsen their own health, while some experienced difficulties breast feeding. This led to supplementation with other milks; herbal teas were given to cure colic and to quench infants' thirst. Based on these findings, the project focused educational efforts on providing better information to mothers. Messages stressed the thirst quenching property of breast milk and its similar benefits to herbal tea, which should be consumed by the mother, rather than the infant. Since breast feeding practices were closely linked to mothers' beliefs about their own needs, the project emphasized the value and needs of the mother and the benefits of breast feeding for her. Educational activities, which continued for 12 months, included videos shown to small groups of mothers, posters, distribution of pamphlets, and messages broadcast over loudspeakers. A significant increase in the number of children aged 0-4 months being exclusively breast fed was observed; however, the increase only occurred in the second, third, and fourth month. This seemed to be a direct result of the decrease in use of herbal teas and sweetened waters. The number of women using other milks as supplements did not decrease significantly.