Information on the potential effect of smoking on the outcome of patient education in asthma is lacking. We randomly allocated 78 asthmatics to either a control or intervention group. Intervention consisted of two 2-h group sessions followed by 1-2 individual sessions each by a nurse and a physiotherapist. Self-management was emphasised following a stepwise treatment plan at exacerbations. Smokers experienced more general practitioner (GP) visits (P=0.001) and absenteeism from work (P=0.02), a greater need for rescue medication (P=0.03), a larger drop in FEV1 (P=0.02) and worse St. George's respiratory questionnaire (SGRQ) scores (P<0.001) compared to non-smokers during the 1-year follow-up. In multiple linear and logistic regression models smoking was still associated with worse SGRQ scores, a drop in FEV1, higher need for GP visits and rescue medication and higher total costs. We, thus, conclude that smoking was associated with reduced health related quality of life, a drop in FEV1, increased need for rescue medication and GP visits and higher costs after patient education during the 1-year follow-up, compared to no smoking.