BACKGROUND: Atopic sensitization to aeroallergens is an essential preceding factor for atopic disorders. The information on the sensitization rates and their changes is an important tool to cope with increasing atopic disorders; however, it is rarely available in Korea. OBJECTIVE: We investigated the prevalence of atopy, the sensitization rates to common aeroallergens and their recent changes. Method: With informed consent, skin prick tests were performed on the study population. Atopy was defined as that one or more positive skin prick test responses (wheal, > or =3 mm) to the 16 common aeroallergens. The prevalence of atopy and the sensitization rates to each allergen were compared with those of previous reports. RESULT: Approximately 7% (1,343, mean age of 13 years) of school children in Jeju were enrolled. Skin tests to the 16 aeroallergens were performed on 1,060 subjects (83%). The prevalence of atopy was 51.9%. House dust mites (HDM), Japanese cedar, Tyrophagus putrescentiae and citrus red mites were frequently sensitized aeroallergens. Comparing with previous reports, the prevalence of atopy and the sensitization rates of HDM, cedar and outdoor moulds were higher. CONCLUSION: Atopy among school children in Jeju is increasing. HDM, Japanese cedar and outdoor moulds are the important aeroallergens which are increasing recently. The increase of atopic disorder may be related to the change of living environment.