Twenty-seven subjects with moderate asthma at the time of diagnosis, well controlled under regular fluticasone propionate (FP) (250 μg b.i.d.) for 6 months at least, were randomized to receive in double-blind fashion: FP 125 μg b.i.d. (Group 1) or FP 50 μg b.i.d. (Group 2) or placebo (Group 3) for 3 months or until symptom recurrence. Daily symptom score and peak expiratory flow were monitored. At the beginning and at the end of the study, subjects underwent methacholine challenge and sputum induction. Recurrence of symptoms occurred shortly after randomization in all subjects receiving placebo. None from Group 1 or 2 experienced symptom recurrence during the study. No significant difference in clinical and functional data, and in sputum eosinophil percentages was observed between the beginning and the end of the study in both Groups 1 and 2. Subjects from Group 3 showed a significant increase of sputum eosinophils ( P<0.05) and a significant decrease in provocative dose of methacholine ( P<0.05) when asthma symptoms recurred. Therefore, very low doses of FP (50 μg b.i.d.) are effective in maintaining for 3 months a good control of the disease in asthmatics already stable under high-dose fluticasone, considering both clinical and functional outcomes and markers of airway inflammation.