OBJECTIVE To investigate whether, after 48 h of IV treatment with corticosteroids, the use of high-dose inhaled flunisolide is as effective as systemic corticosteroids in adults hospitalized for a severe asthma exacerbation. METHODS Randomized, double-blind, placebo-controlled study. METHODS Inpatient, an urban teaching hospital medical ward; outpatient, asthma clinic affiliated with the hospital. METHODS Forty patients aged 18 to 55 years with asthma exacerbation requiring hospitalization. METHODS Inhaled flunisolide via metered-dose inhaler (250 micro g per activation) eight puffs bid compared to systemic corticosteroids alone, following eight doses of IV corticosteroids. RESULTS Peak expiratory flow rate (PEFR), FEV(1), and symptom scores were recorded on day 1 (at presentation to the emergency department) and day 7, at an outpatient follow-up visit. From day 1 to day 7, mean PEFR increased from 190 to 379 L/min in the flunisolide group, and from 207 to 347 L/min in the systemic corticosteroids group (p = 0.95; 95% confidence interval [CI], - 66.3, infinity ). Mean FEV(1) increased from 1.6 to 2.3 L in the flunisolide group, and from 1.4 to 2.1 L in the systemic corticosteroids group (p = 0.33; 95% CI, - 21.7, infinity ). Changes in symptom scores were - 0.7 in the flunisolide group and - 0.9 in the systemic corticosteroids group (p = 0.39; 95% CI, - 0.4, infinity ). Hospital readmission rates on day 7 were zero for both groups. CONCLUSIONS High-dose inhaled corticosteroids are as effective as systemic corticosteroids during a 7-day period following admission to the hospital for severe asthma.