The Bacille Calmette-Guérin (BCG) vaccine is used more than any other vaccines in the world, whereas a lot of studies have spoken about allergy and its relationship with the BCG vaccine. The aim of this study was to determine the relationship between the levels of Thelper1(INF-gamma)/Thelper2 (IL-4, IL-13) in children suffering from Asthma and the scar size of BCG in them. 100 children who have got scar, 60 of them suffered from asthma and 40 did not suffer from it, were studied. The Chi-square test revealed that the frequency of cases with scar size larger than 5mm, is 43%in Asthmatic patients and 70% in control group that the observed difference was statistically significant (P = 0.01). T test also revealed that the average of INF-gamma is considerably lower in patients suffering from Asthma than the control group. (6.95±3.83 (pg/ml) in asthmatic group compared with 10.75±6.98 (pg/ml)in control group)(P = 0.001) wherease the average of IL-4 (30.90±16.51(pg/ml) in asthmatic group compared with9.95±7.44 (pg/ml) in control group) (p<0.001) and IL-13 (48.85±13.66 (pg/ml) in asthmatic group compared with10.49±12.44 (pg/ml) in control group)(p<0.001) is higher. It was demonstrated that the average of INF-gamma/IL-13(0.3054in asthmatic group compared with1. 9334 in control group) in patients suffering from asthma, is lower. The size of BCG scar in Asthmatic patients was, significantly, smaller than the control group. Moreover, the average of Thelper1(INF-gamma) was lower and the average of Thelper2 (IL-4.13) was higher in asthmatic patients. Therefore, there is a correlation between the size of BCG scar and the levels of Thelper1(INF-gamma) and Thelper2 (IL-4.13) with asthma; thus, there could also be a correlation between the scar size of BCG, Thelper1 and 2.