Breast engorgement is a physiological condition during the first two weeks of child birth in which there is lymphatic and vascular congestion and pressure of new milk. It is associated with hard, painful, throbbing, aching, and tender breasts, which may result in women needing analgesia, developing mastitis or temporarily or permanently stopping breastfeeding. The nurse should understand the effect of breast engorgement on the mother and recognize its influence on the baby. One group pre-test - post-test research design was adapted for the study. In view of the nature of the research problem and objectives, a structured questionnaire and structured teaching programme was developed in the initiation of breastfeeding within one hour of birth, composition of breast milk, advantages of breast feeding, techniques and problems of breast of breastfeeding and its management. Sixty primi postnatal mothers were selected by non-probability convenient sampling technique. Structured Knowledge questionnaire was used to collect needed data. After pre-test the structured teaching on prevention and management of breast engorgement was given for 45 minutes. Post-test was administered after five days. The data collected were tabulated and scrutinized by using descriptive and inferential statistics. Results show that 90% of the mothers had an overall inadequate knowledge, 10% of postnatal mothers had moderately adequate knowledge, and none of them had adequate knowledge in pre-test. In post-test 18% had moderately adequate knowledge and 82% of postnatal mothers had adequate knowledge and none of them had inadequate knowledge regarding prevention and management of breast engorgement. The study concludes that the planned teaching programme was effective in improving the knowledge of the postnatal mothers regarding prevention and management of breast engorgement.