Introduction: Growth impairment is a known adverse event (AE) of corticosteroids in children. This study aimed to assess the effect of once-daily (QD) inhaled fluticasone furoate (FF) versus placebo on growth velocity over 1 year in prepubertal children with well-controlled asthma.Materials and Methods: This randomized, double-blind, parallel-group, placebo-controlled, multicenter study (NCT02889809) included prepubertal children, aged 5 to <9 years (boys), and 5 to <8 years (girls), with >= 6 months' asthma history. Children received inhaled placebo QD plus background open-label montelukast QD for a 16-week run-in period and were then randomized 1:1 to receive inhaled FF 50 mu g QD or placebo QD (whilst continuing background open-label montelukast) for a 52-week treatment period. The primary endpoint was the difference in growth velocity (cm/year) over the treatment period. Other growth endpoints were measured, as were incidence of AEs and asthma exacerbation. Growth analyses included all intent-to-treat (ITT) participants with >= 3 post-randomization, on-treatment clinic visit height assessments (GROWTH population).Results: Of 644 children in the run-in period, 477 (mean age 6.2 years, 63% male) entered the 52-week treatment period (ITT population: FF N = 238, placebo N = 239; GROWTH population: N = 457 [FF N = 231; placebo N = 226]). The least-squares mean difference in growth velocity for FF versus placebo was -0.160 cm/year (95% confidence interval: -0.462, 0.142). There were no new safety signals.Conclusions: Over 1 year, FF 50 mu g QD had a minimal effect on growth velocity versus placebo, with no new safety signals.