Forty patients 10 years of age or older with acute Group A streptococcal pharingotonsillitis were treated with the new macrolide Clarithromycin 250 mg bid for 10 days. Minimal Inhibitory concentration to Clarithromycin varied from 0.06 mcg /mI to 0.5 mcg / ml. The clinical cure rate was 97%; 3% presented improvement. The bacteriologic cure rate was 92.5%. Mild adverse reactions were observed In 6 patients. In conclusion Clarithromycin Is an effective and well tolerated drug for Group A streptococcal pharingotonsllitis.