BACKGROUND: A controlled trial of asthma education was conducted but only 51 out of 164 eligible patients participated. METHODS: Differences between subjects who participated in the trial and those who expressed initial interest but subsequently declined were studied. RESULTS: Women, non-smokers, and those whose attending physician was concerned in the study were significantly more likely to attend the programme. Higher socioeconomic status was associated with greater attendance, but this did not reach significance. Psychosocial malfunctioning due to asthma was also associated with attendance, but this was not significant when sex and education level were taken into account. There was no difference between attenders and non-attenders with respect to age, number of previous admissions, airway function, self reported asthma severity, knowledge about asthma, and self management practices. CONCLUSION: The results suggest that many asthmatic patients recovering from a severe exacerbation of airflow obstruction will not participate in hospital based health education programmes. Alternative strategies may be required to improve the self management behaviour of these patients.