A questionnaire survey of the current medical therapy in patients with mild persistent (step 2) asthma was conducted of doctors professing internal medicine in Saitama prefecture. Responses were obtained from 933 of those surveyed (response rate: 53%). Medications frequently prescribed for asthma control were theophylline (77%), inhaled corticosteroids (ICSs: 75%), and leukotriene modifiers (64%). Usage of theophylline in exacerbation reached 87% and was given priority over inhaled beta2-agonist, suggesting too much usage of theophylline among respondents. ICSs were used in 75% of respondents. Doctors specializing in respiratory or allergic medicine used ICSs more frequently than the others. They started ICSs at large doses initially (48%), followed by small doses, and they showed a trend of continuing ICSs after the asthma was under control (75%). Eighty-three percent of respondents used leukotriene modifiers, which were evaluated as easy to administer orally, having a synergistic effect with ICSs, and having fewer side effects compared with other asthma medications.