Objective: To assess the level of knowledge regarding breastfeeding among postpartum mothers who attended immunization clinics in four maternity hospitals in Allahabad, Uttar Pradesh. Design: Descriptive cross-sectional survey design. Setting: Four maternity hospitals in Allahabad, Uttar Pradesh, India. Participants: 400 postpartum mothers (up to 6 months) Methods: The data was collected after obtaining University ethical clearance and administrative permissions from the four maternity hospitals in Allahabad, Uttar Pradesh, India. 400 postpartum mothers who attended the immunization clinics (up to 6 months) were approached through convenience sampling technique. The participants were explained about the purpose of the study. Based on the inclusion and exclusion criteria, the participants were selected. Informed consent was taken from the participants. The demographic data and breastfeeding related knowledge questionnaire was collected from the participants. Results: Only [46(11.5%)] postpartum mothers had good breastfeeding knowledge, [255(63.7%)] had average knowledge and [99(24.8%)] mothers had poor breastfeeding knowledge. The mean knowledge score was 4.94±1.92 (maximum score = 12 with mean score % = 41.16). Conclusions: Mothers knowledge is a key factor for improving breastfeeding rates. The majority of the mothers attending immunization clinics were having insufficient knowledge regarding breastfeeding. This underlines the need for the involvement of health care professionals in educating mothers about breastfeeding. Implications for Practice: While developing countries strive to increase institutional births, there is a growing demand for a healthy atmosphere for breastfeeding in health care facilities. Improving the knowledge of expecting mothers in the antenatal period itself can bring in a lot of change in practice of breastfeeding as breastfeeding knowledge is an important factor for improving breastfeeding outcomes. Antenatal counseling regarding breastfeeding, arrangement of child birth classes to couples, provision of guidance and support, are some of the steps which can enhance confidence in mothers and can lead to successful establishment of breastfeeding.