Patients with bronchial asthma often exhibit irrational fears of cortisone medication beyond justified worries about side-effects. A negative cortisone image, which means overemphasizing the damaging and threatening aspects of cortisone, often underlies non-compliant illness behaviour. In the present study, cortisone image was investigated in 54 patients with bronchial asthma before and after participation in the Düsseldorf Asthma treatment and teaching programme (ATTP) and one year later. By participating in ATTP, a significant reduction of the negative cortisone image and thus a more realistic view of cortisone could be achieved in most patients. This effect was also evident at the follow-up examination one year later. On the other hand, persistence of a negative cortisone image in a subgroup of patients turned out to be a potent predictor of later non-compliant illness behaviour. Psychological implications of a persistent negative cortisone image are discussed.