The study is a part of the European Community Respiratory Health Survey. A random sample (n = 351) of 20-44-year olds and persons of the same age with asthma-like symptoms or current asthma medication according to a postal questionnaire (n = 95) were studied. Interview was taken, methacholine challenge was done and ECP, total and specific IgE were measured from serum. The median S-ECP value was 8.0 micrograms/l in the random sample. The geometric mean of S-ECP was higher in subjects with, than without atopy (10.2 vs 8.9 micrograms/l, P < 0.01) and in subjects with bronchial hyperresponsiveness (BHR) than in subjects without BHR (9.9 vs 8.0 micrograms/l, P < 0.01). The levels correlated weakly to forced expiratory volume in one second (FEV1) (r = 0.13, P < 0.01) and were not independently correlated with respiratory symptoms, asthma or FEV1 after adjusting for BHR, IgE, sensitisation and smoking. Our results indicate that the level of eosinophil activation is low in a population with a low prevalence of atopy, even when BHR is common.