Prevalence of asthma in Australian children is amongst the highest in the world. Although breastfeeding positively influences infants’ immunity, early introduction of Milk Other than Breast Milk (MOTBM) may also play an important role in the development of Asthma. The aim of this study was to investigate the association between the introduction of MOTBM in the first six months after birth and the development of reported persistent asthma in children 3-years old. As sample of 1,121 children were extracted from the Environments for Healthy Living longitudinal birth cohort study. Introduction of MOTBM during the first six months after birth increased the risk of development of persistent asthma by almost two-folds (Adjusted Relative Risk (ARR): 1.71, 95%CI: 1.03-2.83, p= 0.038). This study indicates that the introduction of MOTBM in the first six months of life is a risk factor for asthma incidence among children 3 years old or younger. This result is important in explaining the benefits of breastfeeding as part of public health interventions to encourage mothers to increase breastfeeding initiation and duration and avoid introduction of MOTBM in the first six months after childbirth.