Design
This study included 571 children from 6 to 15 years old age, with pharyngitis, who were admitted to 45 elementary and guidance schools from 7 regions of Education Organization in North-East of Iran, Mashhad. They were screened for enrollment and if he/she presented pharyngitis with clinical criteria of sore throat, erythema, exudate and tender or enlarged anterior cervical lymph nodes. Exclusion criteria included reports of antibiotic use, negative throat culture for GAS and history of allergy to the drugs. Clinical and bacteriologic responses to BPG and once daily orally amoxicillin were considered and compared