According to the World Health Organization, breastfeeding is natural and the most effective way of nourishment to feed infants and young children to ensure child health and survival. Currently, the World Health Organization, the American Academy of Pediatrics, and other health organizations recommend exclusive breastfeeding during the first 6 months of life. Although exclusive breastfeeding has been shown to reduce the occurrence of adverse health outcomes to the infant and mother, the duration of exclusive breastfeeding remains relatively low in the United States. The theory of planned behavior was used as a theoretical framework for this study. The purpose of the project was to identify the barriers to exclusive breastfeeding among mothers during the first four weeks after delivery. A descriptive research design and a convenient sampling method were used to conduct this study. A questionnaire was used to collect the data from 75 mothers who met the inclusion criteria and who attended 3 selected obstetric and gynecologic private practice physicians' offices. Data analysis was performed by using descriptive and correlational statistics. The findings showed that only 8 mothers continued exclusive breastfeeding during the first 4 weeks postpartum. The major maternal problems identified for not continuing exclusive breastfeeding were (a) insufficient breast milk, (b) sore or painful nipples, (c) return to work or school, and (d) poor latching. Findings suggested that healthcare professionals use the model of the theory of planned behavior to develop interventions that promote a positive attitude toward breastfeeding. A positive attitude toward breastfeeding will create a social change within the community to promote exclusive breastfeeding.