• Penicillin remains the drug of choice for the treatment of streptococcal pharyngitis, with erythromycin as an alternative drug for individuals who cannot take penicillin. Two areas of concern in the management of streptococcal pharyngitis are (1) the prevalence of penicillin-tolerant group A β-hemolytic streptococci reported in recent studies and (2) the high prevalence of erythromycin resistance in some geographic areas. We tested 305 isolates of group A β-hemolytic streptococci from Hawaii and the Philippines for penicillin minimum inhibitory concentrations and minimum bactericidal concentrations and erythromycin minimum inhibitory concentrations. There was no evidence of penicillin resistance or tolerance. The prevalence of erythromycin-resistant and moderately susceptible isolates was 3.6% and 2.3%, respectively. There was a trend toward greater erythromycin resistance levels among Hawaiian isolates, but this was not statistically significant.