A lower prevalence of asthma and allergies has been reported among children and adults living in the area of former East Germany compared with those living in West Germany. After German reunification in 1990, the East German population rapidly adopted a western lifestyle. Therefore, this study examined if the prevalence rates of allergic diseases, symptoms, and sensitisation and asthma have increased among East German children since German reunification. - Children aged 5 to 7 years living in the region of Sachsen-Anhalt, East Germany were examined in two cross-sectional studies during 1992-93 (n = 769, response rate 84.0%) and 1995-96 (n = 725, response rate 74.6%). Sensitisation was assessed by specific immunoglobulin E measurements against five common aeroallergens using the CAP-FEIA technique. After adjustment for sex, parental education, season of examination, day care attendance, breast feeding, environmental tobacco smoke exposure, cat dander exposure, and several indoor factors, an increase in the prevalence of self-reported, physician-diagnosed allergies (OR 1.44, 95% CI 1.01-2. 06), but not in allergic sensitisation (OR 0.85, 95% CI 0.62-1.16) was found. The only evidence of an increase in allergies of the self-reported increase in the prevalence of physician-diagnosed allergies is likely due to changes in physician diagnostic patterns and the heightened public awareness of allergic diseases. - In conclusion, there were no significant changes in the prevalence of asthma, allergic rhinitis, or self-reported symptoms of allergic diseases.