Breastfeeding is the most natural experience. It is not only nature's way of providing nourishment but also an important first step in building a relationship between mother and child. However, there are circumstances under which breastfeeding can be problematic. Common problems that arise during the breastfeeding period include breast engorgement, plugged milk ducts, breast infection (mastitis), and sore or painful nipples. These problems can cause distress, mild discomfort, or significant pain, therefore, many women stop breastfeeding a few weeks after delivery. For this reason, this study is conducted to evaluate the effectiveness of a structured teaching program on knowledge regarding breast complications and their management among postnatal mothers in a selected maternity hospital in Bangalore, Karnataka, India.