This study was designed to estimate the prevalence and personal or family history of atopic dermatitis in school children in 3 areas of Korea: urban (Seoul), industrial (Ulsan) and rural (Chunchon). On the basis of dermatologists' physical examinations and the questionnaires completed by parents or guardians, the prevalence of atopic dermatitis was estimated to be 3.3% in the industrial area, 6.6% in the rural area and 7.8% in the urban area. The frequency of atopic dermatitis decreased with age and was significantly lower in the industrial area than in the rural and urban areas.