The resistance mechanisms and clonal relationship were determined for two Streptococcus pyogenes isolates with high-level resistance to levofloxacin as well as to other fluoroquinolones. DNA amplification and sequencing revealed a serine-81→phenylalanine substitution in GyrA and a double substitution in ParC of serine-79→phenylalanine and aspartic acid-91→asparagine. Pulsed-field gel electrophoresis analysis and emm typing determined that both isolates were emm type 28 and were genetically indistinguishable.