OBJECTIVE. To assess the effects of the new inhaled corticosteroid ciclesonide on growth in children with asthma. METHODS. We performed a multicenter, randomized, double-blind, placebo-controlled study to assess the effects of inhaled ciclesonide on growth in children with mild, persistent asthma. After a 6-month run-in period, 661 prepubertal children who were aged 5.0 to 8.5 years were randomly assigned to once-daily morning treatment for 1 year with ciclesonide 40 or 160 μg (ex-actuator) or placebo, followed by a 2-month follow-up period. The primary end point was the linear growth velocity (linear regression estimate) over the double-blind treatment period. Growth was recorded as the median of 4 stadiometer measurements. Adverse events and 10-hour overnight and 24-hour urinary free cortisol levels were also assessed. RESULTS. Mean linear growth velocity during run-in was comparable between groups: 160 μg, 6.20 cm/year; 40 μg, 6.59 cm/year; placebo, 6.49 cm/year. Mean differences from placebo (5.75 cm/year) in growth velocity over the double-blind treatment period were -0.02 cm/year for ciclesonide 40 μg and -0.15 cm/year for ciclesonide 160 μg. Both ciclesonide treatments were noninferior to placebo with respect to growth velocity. The overall incidence of adverse events was comparable between groups, and no significant changes in 10-hour overnight or 24-hour urinary free cortisol levels were noted between groups during the double-blind treatment period. CONCLUSIONS. Ciclesonide demonstrated no detectable effect on childhood growth velocity, even at the highest dosage, which may ease concerns about systemic adverse events. Copyright © 2008 by the American Academy of Pediatrics.