Information for patients provided by the pharmacist is reflected in adhesion to treatment, clinical results and patient quality of life. The objective of this study was to assess an asthma self-management model for rational medicine use. This was a randomized controlled trial with 60 asthmatic patients assigned to attend five modules presented by a pharmacist (intervention group) and 59 patients in the control group. Data collection was performed before and after this 4-month intervention and included an evaluation of asthma knowledge, lifestyle, inhaler techniques, adhesion to treatment, pulmonary function and quality of life. An economic viability analysis was also performed. The intervention group obtained an increase in asthma knowledge scores of 58.3–79.5% (P < 0.001). In this group, there was also an increase in the number of individuals who practiced physical exercise (36–43%), in the number of correct replies regarding the use of inhalers, in the percentage of adherent patients, and in quality of life scores for all domains. We concluded that this asthma self-management model was effective in improving the quality of life of asthma patients.