The frequency of atopic dermatitis in Italian children and its relationship with selected variables were analysed in a large survey of skin health conducted in Italy. In 1997 we conducted a survey on schoolchildren aged 12-17 years from 13 areas of northern, central and southern Italy. For the present analyses, 3179 Caucasian children (1618 males, 1561 females) were considered. A diagnosis of atopic dermatitis was reported in 224 cases (7.0%). The frequency of reported atopic dermatitis was significantly higher in children with asthma (rate ratio (RR) 4.5; 95% confidence interval (CI) 3.1-6.5). The lifetime prevalence of a diagnosis of atopic dermatitis was higher among schoolchildren reporting a diagnosis of psoriasis (RR 5.5, 95% CI 3.0-10.1) and vitiligo (RR 16.1, 95% CI 6.5-39.5). This study gives estimates of the lifetime prevalence of atopic dermatitis in adolescents in Italy and emphasizes the direct association between the condition and other immune-related skin diseases.