Arbekacin (1-N-((S)-4-amino-2-hydroxybutyryl)-3',4'-dideoxykanamycin B) was active against 54 strains of methicillin-resistant Staphylococcus aureus from 16 different countries, all of which were resistant to > or = 32 mg/L amikacin. MICs of arbekacin ranged from 1 to 16 mg/L, the MIC50 was 3.2 mg/L and the mode geometric mean MICs were 4 and 4.5 mg/L respectively.