Oral beta-stimulants, theophylline and oral antiallergic drugs are frequently used for asthma treatment in Japan. However, inhaled beta-stimulants and inhaled steroids are becoming the first and second choice of drugs in asthma treatment in European countries, and these three categories of drugs are becoming third or fourth-line therapeutic choices. Accordingly, we investigated the effectiveness of these drugs, which is limited by their pharmacological actions and effects. As found in this study many cases of bronchial asthma cannot be well controlled by their agents, either alone or in combination. The necessity of these drugs for the treatment of chronic bronchial asthma was investigated. Substitution of inhaled beta-stimulant for oral beta-stimulant was possible in 8 of 15 cases. However, in 7 cases, substitution was impossible because of the patient's complaints, and it could not be concluded that oral beta-stimulants are necessary for asthma treatment. Theophylline was substituted by inhaled corticosteroids in 6 of 8 cases. Oral antiallergic drugs were substituted by inhaled corticosteroids in 5 of 6 cases. These results do not conclusively indicate that theophylline and oral antiallergic drugs are not necessary for asthma treatment.