We aimed to evaluate the efficacy and safety of fluticasone propionate (FP) in children aged 12-47 months with recurrent/persistent asthma symptoms. One hundred and sixty children (12-47 months) were randomised into this multicentre, double-blind, placebo-controlled, parallel-group study, and treated with either FP (100 μg bd) or placebo (2 puffs bd), both administered by metered-dose-inhaler and Babyhaler™ for 12 weeks. The primary endpoint was percentage of symptom-free 24 h periods. Over weeks 1-12, FP-treated patients had significantly more percentage symptom-free 24-h periods compared with placebo (odds ratio 0.53; 95% CI 0.29-0.95; P = 0.035). Relative to baseline, where all patients were symptomatic for at least 21/28 days of the run-in, the improvement equated to one additional symptom-free 24 h period per week. FP patients also had a significantly higher percentage of 24 h periods with no wheeze or cough, the odds ratio for treatment difference corresponding to two additional wheeze-free and one additional cough-free periods per week. FP was well-tolerated, with similar reported adverse events in both groups. Urinary cortisol-creatinine ratio was slightly decreased among FP patients after 12 weeks, but with no clinical correlates. FP is effective for the treatment of chronic persistent asthma symptoms in very young children.