Asthma patients are prime candidates to employ complementary medicine (CM) for their conditions, yet little hard data exist on the prevalence of CM use by these patients. This survey was aimed at generating some information on this and related issues. Members of the UK National Asthma Campaign (17,000) were invited to complete a questionnaire and 4741 responded. Only 41% of the respondents had never tried CM. Breathing techniques, homoeopathy, and herbalism were the three most prevalent treatments. The majority of respondents perceived these therapies as moderately useful with only little difference between various treatments. In general, the money spent on CM was modest. It is concluded that CM is frequently used for asthma. Therefore, this area of healthcare would seem to warrant more rigorous investigation.