Purpose: The objective of this study was to identify differences in the clinical manifestations and allergic indices between monosensitized and polysensitized children. Methods: We reviewed retrospective data from the medical records of patients who had chronic or recurrent respiratory symptoms and visited the pediatric clinic at Chung-Ang University Hospital for an evaluation of allergic diseases from January 2003 to January 2011. The patients were categorized into nonsensitized (n=111), monosensitized (n=149), and polysensitized (n=205) groups according to skin prick tests (as classified by five allergen groups). We compared gender, age, family history, admission history, food sensitization, total immunoglobulin E (IgE), peripheral eosinophil counts, eosinophil cationic protein (ECP) levels, forced expiratory volume in 1 second (FEV1), and methacholine provocation tests among the three groups. Results: The frequency of food sensitivity was highest in the polysensitized group (n=101, 49.3%), followed by the monosensitized (n=8, 5.4%) and nonsensitized groups (n=0) (P<0.001). The FEV1 was significantly lower in the polysensitized group than that in the monosensitized and nonsensitized groups (79.4 ± 20.2% vs. 87.2 ±16.0% vs. 87.6 ± 17.1%, respectively) (P=0.013). The total IgE and ECP levels were significantly higher in the polysensitized patients than those in the other patients (P<0.001 and <0.001, respectively). Differences in gender, age, peripheral eosinophil count, and bronchial hyper-responsiveness were not identified between the monosensitized and polysensitized groups. Conclusion: The polysensitized group showed more frequent food hypersensitivity, lower FEV1 values, and higher allergic indices such as total IgE and ECP, suggesting a different atopic phenotype compared with those in the monosensitized group. (Pediatr Allergy Respir Dis(Korea) 2011;21: 277-284)