In this case-control study the association between the approaches used to feed infants, together with known family and environmental factors, and the occurrence of atopic illness in toddlers between the ages of 4 months to 3 years in Hong Kong was examined. A total of 206 subjects were recruited from April to June of 2014. The results obtained by binary logistic regression indicated that atopy is associated with boys (OR 2.072, CI 1.089–3.941), the maternal use of antibiotics in utero or while breast feeding (OR 2.276, CI 1.151–4.504), the later commencement of mixed feeding (OR 2.497, CI 1.025–6.082), breast feeding exclusively for 3 months (OR 1.972, CI 1.009–3.857), and having a mother who was diagnosed with eczema (OR 4.510, CI 1.764–11.530). Although an exclusive reliance on breast feeding has been shown to be predictive of atopy among toddlers, the positive qualities of breast milk cannot be ignored. A further study of the contents and nutritional values of breast milk is warranted.