Objective : To determine the clinical and bacteriologic efficacy and safety of Cefdinir in acute pharyngitis and pharyngotonsillitis caused by group A beta hemolytic streptococci in pediatric patients. Methods : Children aged 3 through 12 years who visited the hospitals enrolled in this study with signs and symptoms of pharyngitis or pharyngotonsillitis since May to December 2002, were taken throat culture and given Cefdinir(12 mg/kg/day, in three divided doses) for 7 days. Two hundred thirty five patients were enrolled and 90 patients who showed positive culture results were followed up for the signs and symptoms during the treatment to determine clinical efficacy. Follow-up culture were done at the end of the study and bacteriologic efficacy was determined Results : Ninety out of 235 patients who visited the hospitals with the signs and symptoms of pharyngitis showed positive growth on throat culture. Seventy nine patients were clinically and microbiologically assessable. The bacteriologic eradication rates of S. pyogenes were 100% in all the children treated with Cefdinir. Clinical cure rates were not different between less than 7 days-treated group(75%) and just 7 days-treated group(98.6%)(P=0.077). Two patients reported adverse reaction during Cefdinir treatment. Antimicrobial sensitivity of Cefdinir against S. pyogenes was 100% with range of MIC being less than 0.5 ${mu}g/mL$. Conclusion : It seems that Cefdinir is one of reliable and well-tolerated drugs for the treatment of group A beta hemolytic streptococcal pharyngotonsillitis in children. It needs to be investigated short term efficacy in terms of improving drug compliance and impact of economic point of view. We can recognized that still high rate of the erythromycin resistant group A streptococci in our community should be monitored every year.