A total of 323 children aged 4-11 years who were receiving, or had symptoms indicating a clinical requirement for, inhaled corticosteroid at a daily dose of 400 micrograms budesonide (BUD) or beclomethasone dipropionate (BDP), or 200 micrograms fluticasone propionate (FP), were randomised into this multicentre, open-label, parallel group study. Patients received either FP 100 micrograms b.d. administered via the Accuhaler/Diskus inhaler (n = 159) or BUD 200 micrograms b.d. administered via a Turbohaler inhaler (n = 164) for four weeks and recorded daily their morning and evening peak expiratory flow (PEF), asthma symptoms and use of relief medication. Device handling was assessed by a questionnaire, with responses recorded on three- or five-point ordinal scales. The primary efficacy parameter was mean percent predicted morning PEF. The device handling results showed the Accuhaler/Diskus inhaler was rated more favourably than the Turbohaler inhaler in terms of ease of correct inhaler use, ease of telling how many doses were left, ease of knowing whether a dose had been inhaled and overall liking of the device. More patients in the Accuhaler/Diskus group (85%) than in the Turbohaler group (58%) said they would be happy to receive the same device again, while 8% and 25% respectively said they would not be happy to be given it again. In addition, the change from baseline to week 4 of treatment in mean percent predicted morning PEF was greater in the FP Accuhaler/Diskus group, indicating that FP 200 micrograms daily via Accuhaler/Diskus inhaler is at least as clinically effective as BUD 400 micrograms daily via the Turbohaler inhaler.