The issue of compliance with prescribed medication has traditionally been dominated by the perspective of the health professional although increasingly sociologists, using qualitative methods, have begun to present the patients' point of view. However, little has been published on asthma, despite the numbers of people suffering from this chronic condition and the amount of medication regularly prescribed. This paper focuses on the perspective of a sample of S. Wales (U.K.) asthma patients who have all been prescribed prophylactic medication in the last 12 months and explores their attitudes to medication in the context of their everyday lives, using inductive qualitative research methods. Two main groups were identified: the deniers and the accepters. They differed fundamentally in their readiness to accept the identity of asthma sufferer which, in turn, was associated with very different beliefs about the nature of their problem and the meaning of the medication prescribed for it. There was also marked differences in their strategies of self-presentation and disclosure and their pattern of medication use, particularly for prophylactic medication. A third group, the pragmatists, were also identified as a possible sub-group of the accepter category who are less open within self-presentation and less consistent in their beliefs about asthma but do not reject the label entirely. Identity work, i.e. the way the respondents interpreted the social identity of asthma sufferers and managed to reconcile it with other social identities, is proposed as the most useful way of understanding the observed variation in the way people diagnosed as asthmatic conceptualise and use their medication.