The aim of the study was to estimate the prevalence of atopic sensitization and to analyse the relationships between atopic sensitization and respiratory symptoms, asthma, and allergic rhinitis and/or conjunctivitis among adult population aged 17–66 years in the capital of Estonia, Tallinn. A cross-sectional study was carried out between March 1997 and December 1998. Sensitization to 15 inhalant allergens was assessed. The associations between skin prick test (SPT) positivity, the symptoms based on a structured interview, and the possible risk factors were estimated. A random sample of 516 subjects was included in study analysis. The prevalence of atopic sensitization was 34.5%, while it was 39.3% for subjects aged 20–44 years. Sensitization was the highest against the German cockroach, 15.5%, which was followed by mugwort, dog, two storage mite species, and cat dander. Subjects with wheezing due to furred animals, and allergic rhinitis and/or conjunctivitis had a significantly higher prevalence of positive SPT. In conclusion, the prevalence of allergic sensitization among adult population in Tallinn was surprisingly high. Our results suggest that the cockroach allergen should be included in epidemiologic studies in Estonia in order to obtain true assessment of the prevalence of atopic sensitization in Estonia.