This study aimed to compare the efficacy of nebulized therapy with salbutamol alone or in combination with fluticasone. In a randomized, double-blind clinical trial, 150 children with moderate acute asthma were randomly assigned to receive by nebulizations either (i) three doses of salbutamol 30 microl/kg per dose, each dose administered every 15 min, (ii) three doses of salbutamol plus two doses of fluticasone 500 microg/dose at 15 and 30 min after first dose of salbutamol, or (iii) three doses of salbutamol/fluticasone 500 microg/dose, each combined dose administered every 15 min. Pulse oxymetry (SaO2), peak expiratory flow (PEF) and Wood et al. (Am J Dis Child, 123, 1972, 123) clinical scale were evaluated at baseline, 15, 30, 45, 60, 90 and 120 min after the first nebulization. Patients in the three groups significantly improved since 15 min after the first nebulization. We did not observe differences in the recovery of SaO2 and PEF among the three groups of treatment (p > 0.10). In group 3, children showed better clinical response at 120 min than the other two groups (p < 0.05). No significant adverse effects were observed with any treatment. To summarize, in children with acute moderate asthma, nebulized salbutamol at an accumulated dose of 90 mul/kg plus fluticasone at an accumulated dose of 1500 microg produced better clinical relief after 2 h. However, similar PEF and SaO2 responses were observed with salbutamol alone or in combination with different doses of fluticasone.