Breastfeeding is important for the health and well-being of the infant and mother. This benefit continues into later life with a reduction in incidence of a number of chronic diseases. In this book we examine infant feeding practices, including knowledge and attitudes towards breastfeeding and factors that influence the duration of breastfeeding. In addition, we have also examined the impact of additional factors including postpartum women’s body image and perceived changes of breast shape in Australian and Japanese women. Our study included 1,623 mothers from Japan and 587 from Australia. In Japanese mothers the Attention to Body Shape Scale (ABS), showed that they were very conscious of their body shape. Breastfeeding’ to six months was less likely when Japanese mothers were employed, had breastfeeding problems, smoked or perceived changes in breast shape, although the latter did not influence Australian mothers. Where the decision to breastfeed was made before delivery, and for Australian mothers, when the father supported breastfeeding, duration was likely to be longer. These factors should be considered in health promotion programs for breastfeeding.