The severity of asthma varies within and between individuals, and the disease has a variable impact on quality of life. Disease severity can be modified but not cured by long term anti-inflammatory therapy. Compliance with, or adherence to, such therapeutic regimens is difficult, and it is affected by a number of factors. Patterns of compliance are variable; some patients take only half the prescribed drug all the time, while others take all their prescribed medication for a while and then "take a break'. Understandably, there is no single factor that would account for such a variety of human behaviour, but generally the frequency and ease of drug administration, as well as adverse effects (real or imagined), can affect compliance. Poor communication regarding the precise regimen will also impair compliance. Psychosocial factors such as depression, poor interpersonal skills and coping strategies, and rejection of the diagnosis will lead to lower levels of compliance. Interventional programmes using a combination of education, skills training and methods to modify behaviour are needed to improve the quality of life in asthmatics. The role of the newer generations of once-/twice-daily oral anti-inflammatory preparations in improving compliance requires further investigation.