This study assessed the effects of treatment with fluticasone in children younger than 2 years old with recurrent wheezing and risk factors of developing asthma. This double-blind placebo-controlled study randomized children to receive fluticasone (125 mug; n = 14) or placebo (n = 12) twice daily for 6 months. Pulmonary function was assessed at the beginning and end, and parents filled out a daily diary recording respiratory symptoms, need for rescue medication, and emergency care. The SD score of maximum flow at functional residual capacity was -0.74 +/- 0.6 at the beginning and 0.44 +/- 1 at the end for the fluticasone group (p = 0.001), and -0.79 +/- 0.3 at the beginning and -0.78 +/- 1.4 at the end for the placebo group (p = 0.97). A statistically significant difference (p = 0.02) was observed between treatments. The percentage of symptom-free days was 91.3 +/- 7% for fluticasone and 83.9 +/- 10% for placebo (p = 0.05). The number of respiratory exacerbations was 2.1 +/- 1.7 and 4.1 +/- 3 (p = 0.04), and the percentage of days on albuterol was 8.6 +/- 6% and 16.3 +/- 9% (p = 0.028). Treatment with fluticasone twice daily for 6 months improves pulmonary function and clinical outcomes in children with asthma younger than 2 years.