In 2002 authors initiated a US-Ukraine collaborative study on bronchial asthma among 2177 6-8 year old children who resided in Kyiv, Dniprodzerzhinsk and Mariupol, Ukraine in 2002 and who were participants in the Family and Children of Ukraine Longitudinal Cohort Study. The overall goal of the study is to investigate the epidemiology and risk factors for asthma and asthma--related symptoms among these children. The study design comprises of three phases. During the first phase Questionnaires including the International Study of Asthma and Allergies in Childhood (ISAAC) core module on wheeze, as well as questions about other respiratory symptoms (including night cough and phlegm) were given to parents of 2177 children aged 6-8 years. The authors examined the prevalence of wheezing and dry cough at night not associated with colds during the past year among the surveyed children. The parent-reported prevalence of wheezing was significantly different among these three Ukrainian cities: 14.4% in Kyiv, 19% in Mariupol and 5.7% in Dniprodzerzhinsk. The prevalence of dry cough at night not associated with colds was also different in Kyiv, Mariupol and Dniprodzerzhinsk and was 11.4%, 6.9% and 6.9% respectively). The authors conclude that the prevalence of wheezing illness and dry cough at night not associated with colds during the past year varies among Ukrainian cities with the highest prevalence in kyiv, the most "westernized" of these cities.