Background: Complementary and alternative medicines are increasingly used for the treatment of asthma worldwide. A five-herb herbal formula (CUF) has been found to be effective and safe in an animal model of asthma and in a preliminary clinical study. Objective: The objective of this study was to evaluate the safety and efficacy of CUF in children suffering from asthma. Design: A randomized, double blind, and placebo-controlled, parallel study. Interventions: Subjects received CUF or placebo for 6 months. Efficacy variables included changes in forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), Paediatric Asthma Quality of Life Questionnaire (PAQLQ), and steroidal consumption. Results: A total of 100 asthmatic children were enrolled and assigned to two treatment groups. The first group received CUF 6 capsules (3 g/day) and the second group received placebo. There was a statistically significant difference in mean spirometric indexes in CUF group at baseline and follow-up visits. In the CUF group, the activity domain showed significant improvement (p = 0.045). FEV% was significantly improved in the CUF group (p < 0.05) compared with the Placebo group. FEV1 also showed significant improvement after eight weeks of treatment. The requirement for steroids decreased after treatment in both groups, and no significant difference was noted between the two study groups. Conclusion: A beneficial role for CUF therapy in pediatric asthma is demonstrated. It improved the pulmonary functions of the children, namely, FEV1 and FVC. However, further research on a larger scale is warranted.