Abstract Objective: The efficacy of ciclesonide 160 μg QD (given either in the morning or evening) was compared with budesonide 200 μg BID in adults with stable asthma that was pretreated with inhaled corticosteroids. Methods: This was a randomized, 3-arm, parallel-groupstudy comparing ciclesonide (given in a double-blind, double-dummy regimen) with open-label budesonide. After 2 to 2.5 weeks, during which patients were treated with budesonide 200 μg BID, patients (n = 405) were randomly assigned to receive ciclesonide 160 μg QD AM or 160 μg QD pm, or budesonide 200 μg BID (all administered by metered-dose inhaler) for 12 weeks. All patients received 2 puffs of medication (or placebo) in the morning and evening. The primary efficacy variable was the difference in spirometric forced expiratory volume in 1 second (FEV 1 in liters) from randomization to study end. Secondary efficacy end points were forced vital capacity, peak expiratory flow by spirometry, and diary assessments of peak expiratory flow, asthma symptoms, and rescue medication use. Adverse events were assessed by patient report, investigator observation, physical examination, and laboratory testing; events were classified as mild, moderate, or severe. Results: Baseline demographic characteristics with regard to sex, age, weight, smoking status, baseline medication use, and FEV 1 were balanced among the treatment groups. Over the course of treatment, both ciclesonide and budesonide maintained FEV 1 compared with baseline. Both ciclesonide regimens were as effective as budesonide 200 μg BID in maintaining FEV 1 during the treatment period versus baseline (ciclesonide 160 μg QD am: 95% CI, −0.120 to 0.045 vs budesonide; P = NS; ciclesonide 160 μg QD pm: 95% CI, −0.061 to 0.105 vs budesonide; P = NS). Ciclesonide 160 μg QD (morning or evening) was comparable with budesonide 200 μg BID for maintaining pulmonary function, asthma symptom scores, and rescue medication use. The incidence of adverse events was not significantly different among the treatment groups, and most adverse events were not related to study medication. Conclusions: In this study, ciclesonide 160 μg QDwas as effective as budesonide 200 μg BID (400 μg total daily dose) in these adults with persistent asthma. Both treatments were well tolerated.