Background and objectives:- Antimicrobial treatment of GABHS pharyngitis is aimed at reduction of poststreptococcal complications, symptoms, duration, and disease spread. The main goal of our study will be to assess the effect of therapy by long acting penicillin single injection per month versus oral penicillin for 10 days in treatment of children with recurrent streptococcal tonsillopharyngitis by frequent estimation of antistreptolysin o titre (ASOT). Method: Prospective study was done on 50 children suffering from recurrent follicular tonsillitis with high level of anti-streptococcal antibodies (ASOT) (>400 Todd units), age ranges from 3 to 13 years. . The children were classified into 2 groups, group (1) included 25 children had been treated with oral penicillin V (phenoxy methyl penicillin) 10mg/kg/day for 10 days. Group (2) included 25 children had been treated with long acting penicillin single injection of 1.200.000 IU for children >25 KG and 600.000 IU for those