Aim. To assess the bronchodilatory effect of loratadine in children with mild-to-moderate asthma and to determine whether loratadine interacts with terbutaline. Methods: The effect on pulmonary functions on a 10 mg oral dose of loratadine, with and without inhaled terbutaline powder (0.5 mg), was determined in 13 patients with a mean (SE) age of 10.63 (0.77) years (range from eight to 17 years) at 11 time points during 8 h in a randomized, double-blind, placebo controlled, crossover study. Forced expiratory volume in 1 s (FEV1) was the primary measure of efficacy. Results. Although loratadine alone produced an increase in FEV1 relative to baseline this was not statistically significant (p < 0.05). Terbutaline with, and without loratadine, significantly increased FEV1 from 1 to 5 h according to baseline (p < 0.004). When compared with the palcebo, loratadine significantly increased FEV1 from 150 min to 8 h (p < 0.05). Also, terbutaline alone, or in combination with loratadine, significantly increased FEV1 from 30 min to 7 h (p < 0.04 from 30 min to 5 h; p < 0.05, between 6-7 h). Although the mean increase in FEV1, with terbutaline + loratadine in combination, was greater than with terbutaline alone, the difference was not significant (p > 0.05). Conclusion. Loratadine has a mild bronchodilatory effect in the study period and does not interfere with the bronchodilatory effect of terbutaline in childhood asthma.