There is evidence that the prevalence of allergies and asthma differs between populations in western and eastern Europe. This study investigated the prevalence of wheezing, rhinitis and eczema among schoolchildren in urban and rural areas of Scandinavia and the formerly socialist countries of Eastern Europe. A total of 79,000 children from two age groups (13-14 yrs and 6-7 yrs) in 18 study centres responded to a questionnaire within the International Study of Asthma and Allergy in Children (ISAAC). The 12 month period prevalence of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema was calculated. The prevalence of wheezing among the 13-14 yr old children was 11.2-19.7% in Finland and Sweden, 7.6-8.5% in Estonia, Latvia and Poland and 2.6-5.9% in Albania, Romania, Russia, Georgia and Uzbekistan (except Samarkand). The prevalence of itching eyes and flexural dermatitis varied in a similar manner between the three regions. The regional differences were less pronounced among the 6-7 yr old children in the seven participating centres. The highest prevalence of rhinitis was recorded in April-July in Scandinavia and during the winter months in the other countries. The prevalence of atopy-related disorders was higher in Scandinavia than in Estonia, Latvia and Poland, which in turn had a higher prevalence than five other countries of eastern Europe with a culture less similar to western Europe. This supports the hypothesis that "Western life style" is associated with a high prevalence of childhood allergy.