This study evaluated the superiority of combination therapy over steroid therapy alone by using clinical and laboratory data including interleukin (IL)-13 and interferon (IFN) gamma, which participate in the characteristic inflammation and have not been studied to evaluate the efficiency of asthma treatment sufficiently. Moderate persistent asthma patients, aged 7-17 years were included in the study. Patients were randomized to three groups. Group 1 used inhaled budesonide, group 2 used inhaled budesonide plus inhaled formoterol fumarate, and group 3 used inhaled budesonide and oral montelukast sodium therapy. At the beginning and at the end of the 2nd month a detailed physical examination and clinical evaluation; total IgE levels and total eosinophil count in peripheral venous blood, serum IL-13, and IFN-gamma levels; pulmonary function tests; and an assessment questionnaire (Pediatric Asthma Quality-of-Life Questionnaire with Standardized Activities [PAQLQ{S}] were performed. Sixty-seven patients completed the study. Serum IL-13 levels and PAQLQ(S) scores before the therapy and serum IL-13 levels after the therapy were significantly different between the groups and other parameters did not show any significant differences. Serum IgE level was decreased after the therapy in group I and increased in groups 2 and 3, but the difference was insignificant. In all groups total eosinophil levels were decreased insignificantly. After the therapy, IL-13 levels were decreased in groups 1 and 2 and increased in group 3, but the difference was not statistically significant. When compared with the levels before the therapy IFN-gamma levels were decreased after the therapy but the difference was not statistically significant. When the improvement rates for IgE, total eosinophil, IL-13, and IFN-gamma levels and each parameter of respiratory function tests were compared, there were no significant differences between the therapy groups. In all groups PAQLQ(S) scores were significantly improved after the therapy. Our results showed that steroid and other agent combinations do not have any superiority to steroids only; but according to pulmonary function tests and clinical indicators, all three therapy models are effective. These results suggested that the inhalation steroids, as the oldest agents, are still preserving their place and importance in asthma therapy.