To test the hypothesis that surfactant nebulization improves pulmonary function and reduces bronchial responsiveness to histamine, we studied 12 children with asthma. We measured before and after inhalation of 100 mg nebulized natural-derived bovine surfactant (Alveofact (registered)) and after nebulization of 0.9% NaCl the change in peak expiratory flow, vital VC, FEV1, and forced expiratory flows at 50 and 75% of the flow-volume curve. In addition, we performed a histamine inhalation challenge. We did not find any significant changes in these parameters after nebulization of surfactant. These findings indicate that the inhalation of nebulized surfactant does not alter airflow obstruction and does not alter bronchial responsiveness to histamine in asthmatic children with airflow obstruction.