Although the advantages of breastfeeding, such as nutritional and immunologic support to the baby and improvement of emotional bonding between mother and baby, are well recognized, economic benefits of the breastfeeding are not emphasized. Breastfeeding help mothers save money to purchase breast milk substitutes and related equipments, such as bottles, nipples and sterilizers. It also reduces the incidences of common respiratory and gastrointestinal infection of babies, premenopausal breast cancer and ovarian cancer of mothers, and related hospital expenses. For employed mothers, a hospital visit due to illness of their babies can cause absence from their work places. For estimation of the economic advantages of breastfeeding in Korea, we surveyed the cost of the breast milk substitutes and related equipments. The yearly costs for the formulas were 763 thousand to 2.5 million wons, and for the equipment was 360 to 480 thousand wons. If the breastfeeding rate of the total population increased to 50%, 162-294 billion wons can be saved per year in this country by reducing the costs for the formula at the equipment. Total hospital expenses for the illness of babies can be reduced by 7.9-13.8 billion wons per year and hospital costs for maternal breast and ovarian cancers can be reduced by 24.8-57.7 billion wons per year. Durations of maternal absence from their work can be reduced to the value of 21.6-42.5 billion wons per year. In summary, by increasing breastfeeding rates in this country to 50%, 216.4-407.5 billion wons can be saved every year.