The current guideline of the German Respiratory League (Deutsche Atemwegsliga) recommends the synergistic combination therapy with long acting beta 2-agonists and inhalative corticosteroids only for patients suffering from moderate to severe persistent asthma (step 3 and 4 of the asthma severity scale). Now convenient fixed combinations of these substances are available, which could enhance patient's compliance. A large, randomised, parallel-group study in 8000 mild to moderate asthmatics was designed to compare a flexible asthma control plan with the conventional fixed-dose management with respect to quality of life, symptom control and treatment costs. The fixed combination of 6 micrograms Formoterol and 200 micrograms Budesonide per puff in a new dry powder device was applied either due to a novel flexible asthma control plan "ATACO" (group A) or as a standardised conventional dosing regimen (group B) inhaling two puffs b.i.d. In group A (ATACO) patients reduce the run-in dose after four weeks from two puffs b.i.d. to one puff b.i.d. with the option of doubling the dose immediately, if (pre-defined) asthma deterioration occurs. One week later the dose can be either doubled again or reduced due to the actual asthma symptoms of the patient. After run-in, group B patients continue to take two inhalations b.i.d. In this group, asthma exacerbations will be managed as usual by the physician. In contrast, the ATACO group flexible management plan allows the self-medication: an immediate increase in the dose of the fixed combination will lead to both a fast relief of bronchospasm and an automatically higher dosed corticosteroid treatment for the underlying asthmatic inflammation. Conversely, if later asthma symptoms improve, less reliever and controller medication will be needed and used. The immediate treatment of new onset bronchospasm and asthmatic inflammation by the patient himself could maintain at least the same grade of asthma control, as the conventional group B treatment, improve asthma-related quality of life and decrease treatment costs. If the concept works, fixed combinations of long-acting beta 2 agonists and inhalative corticosteroids could have an impact on future asthma guidelines.