Does the prevalence of respiratory symptoms differ between regions? As a part of the European Community Respiratory Health Survey, we present data from an international questionnaire on asthma symptoms occurring during a 12 month period, smoking and symptoms of chronic bronchitis. The questionnaire was mailed to 10,800 persons aged 20-44 yrs living in three regions of Sweden (Västerbotten, Uppsala and Göteborg) with different environmental characteristics. The total response rate was 86%. Wheezing was reported by 20.5%, and the combination of wheezing without a cold and wheezing with breathlessness by 7.4%. The use of asthma medication was reported by 5.3%. Long-term cough and/or morning cough together with problems with phlegm was reported by 12.8%; the prevalence being highest in the most polluted area (Göteborg). When using multivariate analysis, no significant difference in asthma-related symptoms was found between the centres. Women reported cough more frequently, but otherwise gender did not influence symptom prevalence. Our results indicate that bronchitis symptoms occur more frequently in Göteborg, the most polluted of the Swedish centres, but that the prevalence rates of asthma-related symptoms do not differ between these three regions.