Breast problem is one of the commonest problems seen in postnatal mothers in the peuperium. If this problem is not treated properly it can affect the lactation and lead to breast problems or cancer. Awareness of the breast problems and care of breast from the antenatal period will help the mothers to prevent from breast problems. This study attempts to assess the knowledge of antenatal mothers regarding breast problems and create awareness on breast problems. A non-experimental descriptive design was adopted. Data was collected from purposively selected 100 antenatal mothers attending antenatal OPD of Yenepoya Medical College Hospital, Mangaluru using structured interview schedule. The results revealed that majority (76%) of antenatal mothers had inadequate knowledge, 23% had average knowledge and very few (1%) had adequate knowledge regarding breast problems. The mean knowledge score was 12.77 ± 4.32. There was a significant association between the level of knowledge and type of family occupation, family income and previous information (P < 0.05). Most of the antenatal mothers have inadequate knowledge regarding the breast problems. Hence creating awareness about breast care in antenatal period is essential.