Background and Objectives: Because inhaled corticosteroids (ICS) play a central role in the management of asthma, new drug delivery systems for fluticasone propionate, Diskhaler (FPdh) and Diskus (FPdk), were developed. However, few studies have focused on compliance with these drug delivery systems, which can influence drug efficacy. Hence, we compared compliance with FPdk versus that with FPdh. Methods: Data were obtained from a survey of pharmacists dispensing anti-asthmatic drugs to adult asthma patients who visited participating pharmacies between October 2002 and November 2003. Patients were limited to regular users of FPdh or FPdk whose medication and daily administration frequency of ICS were evaluated on the basis of pharmaceutical records. Data on asthma status and various other factors affecting ICS compliance were obtained by questionnaire. Results: Data were acquired on 337 patients. There were no significant differences in gender, age, and duration between the FPdk and FPdh groups. Although FPdk compliance was significantly higher than that of FPdh, conversely there was no significant difference in daily dose and administration frequency between the 2 groups. Furthermore, there was no significant difference in the rate of concomitant drug and in various influencing factors associated with drug compliance. Regarding compliance of concomitant drug, that of oral sustained-released theophylline was significantly lower in FPdk versus FPdh users. Conclusion: In the area of drug compliance, FPdk is superior to FPdh. Although the reason for this is unclear, it is probably due to the characteristics of FPdk itself. Copyright (C) 2006 S. Karger AG, Basel.