An Internet-based questionnaire study involving patients with asthma and chronic obstructive pulmonary disease (COPD) and parents of children with asthma was conducted to evaluate adherence to treatment, and convenience of inhalation and transdermal formulations. Valid responses were obtained from 1470 patients. Among asthmatic patients, the percentage of those who selected "taking as prescribed" was 52.7% for inhalant users and 83.2% for transdermal users. Among patients with COPD, the corresponding values were 54.7% and 86.6%. There was a significant difference (p<0.01) in treatment compliance between inhalation and transdermal formulations in both groups. The most common reason for poor adherence was "frequency of administration", and 83.2% of the patients preferred a once-daily administration. In addition, patients who had used both types of formulations preferred the transdermal ones. In conclusion, health care professionals should further educate their patients about the importance of treatment with inhalants, since poor adherence to treatment with inhalation formulations significantly hinders achievement of optimal efficacy. In addition, transdermal tulobuterol patch, which is administered once daily as a long-acting, beta(2)-agonist, appeared to be useful for long-term control of both asthma and COPD.