Bronchial asthma is a chronic respiratory disease that is worldwide distributed. Its prevalence increases by 50% every 10 years. Several risk factors have been identified. The socio-economic state may be implicated in the morbidity of the disease. Exercise-induced asthma [EIA] is a very common phenomenon especially among children. The objectives of this study were: first, to assess the implication of the socio-economic state on the morbidity of asthma disease, second, to assess the physiological effect of 12-week rehabilitation program [RP] on: baseline pulmonary functions, severity of asthma disease, and response to exercise in 150 primary school children [6 – 12 years] with mild to moderate asthma. Significant positive correlations have been found between the clinical severity score [CSS] & the number of persons sharing the same bed [P=0.044] and between the airway reactivity score [AWRS] & the family size [P = 0.02]. Moreover, an indirect relationship was detected between baseline forced expiratory volume in one second FEV, [% predicted] and family size [P = 0.02]. RP resulted in significant reduction in CSS and AWRS [mean + SD] [from 19.42 ± 6.11 to 12.15 ± 3.77 and from 10.59 4.82 to 6.56 ± 3.13 respectively], as well as significant increase in baseline pulmonary functions [FVC, FEV,, FEF25% - 75%] . Furthermore, RP resulted in significant increase in exercise heart rate [from 146.19 ± 17.59 to 152.12 ± 17.24 beats/min], work load [from 43.76 ± 14.45 to 56.43 ± 18.66 watt)], lowest post-exercise FEV, [from 1.41 ± 0.36 to 1.70 ± 0.36 L] together with decrease in the percent reduction in FEV, after exercise [from 15.27 ± 12.15% to 5.80 ± 5.70%] [mean ± SD] [P < 0.001]. Before RP 59 children out of the 150 [39.33%] developed exercise-induced bronchoconstriction [exercise responders before program, ERB] i.e. 15% or more reduction in baseline FEV,, whereas 13 cases only of them [8.67%] still had exercise induced bronchoconstriction after RP [exercise responder after program, ERA]. The ERB developed significant improvement in their baseline pulmonary functions after RP, whereas the ERA did not develop such improvement although they exhibited significant decrease in CSS and AWRS. In conclusion, the socio-economic state plays an important role in the morbidity of asthma disease. The exposure to respiratory infection and the bad ventilation of bedroom affect the quality of life adversely. The mild to moderate asthmatic children benefit from the rehabilitation program by improving: their quality of life, baseline pulmonary functions, severity of disease, and by decreasing the incidence, as well as the severity of exercise-induced asthma.