Aim. To study the incidence of respiratory symptoms and to reveal their associations with serum cotinine levels (SCL) in 25—45-year-old Novosibirsk dwellers. Subjects and methods. The WHO respiratory symptom questionnaire and the ECRHS screening questionnaire were used for a population-based survey conducted in Novosibirsk to identify respiratory symptoms; 545 people replied to the questions available in the questionnaires. SCL was determined by enzyme immunoassay on a random subsample of 182 examinees. Results. The incidence of respiratory symptoms was determined among the 25—45-year-old Novosibirsk dwellers: cough (27.7%), more than 3-month cough per year (22%), sputum discharge (25%), forced respiration/wheezing in the past year (22.6%), suffocation fits in the past year (5.3%), and cough/forced respiration/stertor bouts by breathing cold air (14.9%) or contacting animals, plants, or chemical agents (16.5%). There was a significant positive correlation between SCL and the presence of cough, more than 3-month cough per year, sputum discharge, forced respiration/wheezing in the past year (compared to the examinees who did not report these symptoms). The median SCL proved to be significantly higher in the people who complained of cough, more than 3-month cough per year, sputum discharge, and forced respiration/wheezing in the past year (compared to the examinees who did not report these symptoms). The people who had a SCL of more than 3 ng/ml were ascertained to be at higher risk of cough, more than 3-month cough per year, sputum discharge, and forced respiration/wheezing in the past year than those who had a SCL of less than 3 ng/ml. Conclusion. The incidence of respiratory symptoms was determined among the 25-45-year-old Novosibirsk dwellers; SCL was found to be associated with the symptoms characteristic of bronchial obstructive diseases; the expediency of using the SCL threshold of 3 ng/ml as a marker of tobacco smoking was confirmed.