There is a growing evidence that strongly immunogenic bacterial vaccnes ( espicially mycobacterial ) can be of therapeutic potential to patients with allergiv bronchial asthma . this was claimed to rsponse of Th-2 lymphocytes twardes the antiinflammatory Th-1 response We carried out this study to evaluate effect of single and repeated BCG vaccination on lung function , serum total IgE and Th-2 lymphocyte cytokine response in allergic asthmatics . The study included 24 young adults with moderate persistant asthma divided into two groups : 12 patients each . One group given single injection of 0.1 ml of BCG while the other given repeated weekly injections of 4 weeks . FEV1% predected , serum total IgE , serum IL-4 and IL-5 were measured before ,one and two months after the 1st BCG injection . We found significant improvement in FEV1 % predected in the whole group and in both groups ( but not reached normal values ) ( p 0.05 for all ). Serum total IgE was significantly lowered only after 2 months and in patients given repeated BCG ( p 0.05 for both ) . IL-5 was significantly lowered 1 and 2 monthes but only in repeated injection group ( p 0.05) . We found non significant positive correlation between the size of tuberculin reaction and FEV1% predected while the reactionwas negative and also non significant with IgE , IL-4 and IL-5 ( r =0.282 , - 0.267 ,- 0.385 and – 0.358 respectively ). We conclude that BCG vacction (espicially if repeated ) can be of benefit to patients with allergic asthma.