This review considers some of the many reasons why researchers and policy makers are increasingly concerned about breastfeeding (BF). It discusses the contraceptive effect and health benefits of BF, and review major BF trends and patterns in selected countries and areas of Asia. It also discusses the complementarity between BF and contraceptive use, and highlights the findings of the studies contained in this special issue of the "Journal." In populations without access to modern contraception, birth intervals (BIs) are determined by the length of BF. The contraceptive effect of BF has been well documented. BF plays an important role in child nutrition and health in 3rd world countries. There are lower incidence of infant morbidity in Asia. Maternal antibodies in breast milk protect the infant from gastrointestinal illness and respiratory infections. Breastfeeding is very economical. The risk of transmission of the human immunodeficiency virus which causes the acquired immunodeficiency syndrome from the infected mother to the child in the breast milk is a new contraindication to BF. However, BF is not as effective as a contraceptive after 6 months. Modern methods of postpartum contraception must be used. Introduction of contraceptive pills in some setting may be done too early. Family planning programs can help women use BF as a contraceptive method. BF should be seen as a "lactational amenorrhea method" in the "cafeteria" of FP methods. Users of the lactational amenorrhea method need to be represented in service statistics. FP surveys should find out if BR is used for fertility regulation. The other articles in the journal are summarized.