Background: Increasing breastfeeding duration may help physician mothers better counsel their patients. To improve the breastfeeding duration of physician mothers, the factors that may influence their breastfeeding duration should be known. Research Aim: To investigate the breastfeeding behavior and duration among physician mothers and to determine the factors that influence breastfeeding practices. Methods: This was an online prospective cross-sectional self-report survey. A 26-item author-created data-collecting tool inquiring sociodemographic and work characteristics, medical history of delivery, and breastfeeding history was sent to female physicians who had infants between 12 and 60 months of age via an online social group, "Physician Mothers," with 11,632 members. Participants (N = 615) responded, and descriptive statistics were analyzed. Results: Participants' mean duration of exclusive breastfeeding was 4.8 months (SD = 1.9). The total breastfeeding length was a mean 15.8 months (SD = 7.6). The rate of breastfeeding duration for at least 24 months was 17.8% (n = 75). The most common reason for weaning from breastfeeding was workplace-related conditions (23.6%, n = 145). Participants reported that the mean time of resuming night shifts after delivery was 8.6 months (SD = 4.7). The rate of participants who were unable to use their breastfeeding leave rights partially or completely was 43.6% (n = 268). Conclusion: Although legislation is in place to allow working mothers to breastfeed their infants, these legal rights were not used properly. Physician mothers should be fully supported in using their breastfeeding leave rights, and workplace conditions should be improved to enable physician mothers to breastfeed their infants for extended periods.