Asthma control is the cornerstone of monitoring for patients with this disease. Monitoring limited to questions of the type "how is your asthma?" underestimates the real effects of the disease. Measuring control requires assessing several criteria, which differ by the kinetics of their course during treatment. Basing monitoring on only a single criterion risks overestimating control, stepping down treatment too early, and losing control of the disease. In the case of inadequate control, uncontrolled comorbid conditions and aggravating factors or poor treatment adhesion must be sought before determining that the treatment itself is insufficient. After stepping up treatment, the chances of obtaining adequate control increase progressively with time, for at least a year. When the physician and patient jointly determine that the current treatment is the maximum acceptable, waiting may be a solution. Similarly, in seeking the minimal efficacious treatment, treatment must not be stepped down too rapidly. Once control is obtained, continuation of the treatment maintains long-term control for most patients.