This is the author's final draft of the paper published as Clinical and Experimental Allergy, 2007, 37 (12), pp. 1738-1746. The final version is available from http://www3.interscience.wiley.com/. Doi: 10.1111/j.1365-2222.2007.02784.x ; Background: Epidemiological data for south Asian children in the UK are contradictory, showing a lower prevalence of wheeze, but a higher rate of medical consultations and admissions for asthma compared to white children. These studies have not distinguished different asthma phenotypes or controlled for varying environmental exposures. Objective: To compare the prevalence of wheeze and related health-service use in south Asian and white preschool children in the UK, taking into account wheeze phenotype (viral and multiple wheeze) and environmental exposures. Methods: A postal questionnaire was completed by parents of a population-based sample of 4366 white and 1714 south Asian children aged 1 to 4 years in Leicestershire, UK. Children were classified as having viral wheeze or multiple trigger wheeze. Results: Prevalence of current wheeze was 35.6% in white and 25.5% in south Asian one year-olds (p