The severity of asthma can be judged by many features, including the need for medication and associated side effects. Since asthma has both acute and chronic characteristics, therapeutic regimens should be valuable as an instrument to define disease severity and the consequence of intervention. However, because of the variability of asthma severity within each patient, medication quantitation as an index of asthma severity is not without difficulty and limitation. Furthermore, the philosophy of asthma therapy has undergone changes over the past decade. Previously, anti-inflammatory therapy was reserved for only the most severely ill patients. Now, inflammation is recognized as a critical component of asthma, and all patients with active asthma (other than mild symptoms) are recommended to use anti-inflammatory therapy. Although there is little published experience with treatment regimens as an index of disease severity, those that have been used have found validity and reproducibility with this approach. In this paper, a scoring approach to medication use is recommended. Medication is classified into bronchodilator (β-agonists, theophylline, and anticholinergic) or anti-inflammatory (corticosteroid and cromolyn sodium). Medication scores are given on either a per-use or a new-dosage basis. Furthermore, the eight medications are stratified according to potency (i.e., inhaled corticosteroid < oral corticosteroid < parenteral corticosteroid). From this approach, the severity of an individual patient's asthma can be quantitated, and this value can serve as one instrument to assess disease severity.