Data on Staphylococcus aureus strains isolated at various areas in Japan during 1992 and 1993 were collected and analysed. Among 7,033 strains examined, 60.3% were methicillin-resistant S. aureus (MRSA), 86% of which were isolated from inpatients. MRSA were isolated most often (38%) from departments of internal medicine, followed by departments of surgery (13%). The most frequent source of MRSA was sputa (38%), followed by pus (18%). As for coagulase types, 69% of MRSA were Type II and next most frequent was Type VII (24%). Among MSSA strains, Type VII (35%) and Type III (32%) were the most frequent. Frequencies of beta-lactamase-producing strains were 68% in MRSA and 59% in MSSA. More than 80% of MRSA strains were resistant to beta-lactams. The frequencies of resistance to fosfomycin, ofloxacin, minocycline and gentamicin were 88%, 72%, 19% and 66%, respectively. Less than 3% of MRSA strains were resistant to arbekacin or vancomycin.