Purpose: Chronic cough is one of the major symptoms of asthma and allergic sensitization and may appear prior to the onset of asthma. The object of this study was to investigate the risk of allergic sensitization in preschool children with chronic cough. Methods: We reviewed the medical records of 99 preschool children presenting with chronic cough but not with allergic rhinitis, atopic dermatitis, recurrent wheezing, or lower respiratory tract infection between November 2011 and July 2013. Results: Fifty-four children (55%) were sensitized at least one of the following inhalant allergens: Dermatophagoides pteronyssinus, Dermatophagoides farinae, cockroach, Alternaria alternata, dog dander, and cat epithelium. Children with allergic sensitization had a higher blood total IgE levels transformed by common logarithm (1.9±0.6 IU/mL vs. 1.3±0.5 IU/mL, P<0.001) and eosinophils (3.7%±2.5% vs. 2.7%±2.0%, P=0.043), more frequent parental history of allergy (68% vs. 48%, P=0.044) and less frequent history of breast milk feeding (68% vs. 86%, P=0.041) than those without. Conclusion: These results suggest that the ratio of allergic sensitization may be 50% or more in preschool children with chronic cough and that parental history of allergy and formula milk feeding may be associated with allergic sensitization. (Allergy Asthma Respir Dis 2015;3:105-108)