We have performed 24-week open-labeled comparative randomized parallel-group study of the basic therapy efficacy of uncontrolled and partly controlled atopic asthma children with magnesium deficiency. The additional correction of magnesium deficiency increases the efficacy of atopic asthma basic therapy. It leads to more pronounced inhibition of local allergic inflammation in respiratory system, decreases the exacerbation frequency (9.5%, p = 0.02), and increases the number of asymptomatic days and the 12-week constant asthma control frequency (71.4%, p = 0.145) as compared to the group without magnesium deficiency correction.