This double-blind study aimed to determine whether superior asthma control is achieved with budesonide (Pulmicort Turbohaler) at a loading dose (LD) (400 micrograms b.d.) for 6 weeks, followed by step down to 400 micrograms nocte for 12 weeks, compared with a static dose (SD) (400 micrograms nocte) for 18 weeks. A total of 682 patients (mean peak expiratory flow rate (PEFR) 413 l/min), who demonstrated > or = 15% reversibility in PEFR, were randomised into the study. After 18 weeks, patients experienced improvements in morning PEFR (+45 l/min, both groups), symptom score (LD -0.57, SD -0.49, on a scale of 0-3), sleep disturbance (LD -1.21 nights/week, SD -1.06 nights/week) and beta 2-agonist use (LD -1.36 puffs/day, SD -1.06 puffs/day), within both groups (each p = 0.0001). At 18 weeks, 82% (LD) and 84% (SD) of patients benefited from no nocturnal wakening in the previous 7 days. Overall, at 18 weeks, asthma control was not significantly different between the groups. After 6 weeks, improvements in morning PEFR (LD +36 l/min, SD +26 l/min) and beta 2-agonist use (LD -1.10 puffs/day, SD -0.94 puffs/day) were greater in the loading dose than in the static dose group (each p < 0.05). The greater improvement in morning PEFR in the loading dose group was significant by day 7 (p < 0.05). While both regimens are equally effective in achieving asthma control at 18 weeks, early clinical advantage is gained with initial loading dose budesonide (400 micrograms b.d.).