We measured the in-vitro susceptibility of 833 Staphylococcus aureus strains, isolated from skin infections at our hospital between July 1994 and November 2000, to 13 antimicrobial agents (ampicillin, methicillin, cephalexin, cefaclor, cefpodoxime proxetil, gentamicin, erythromycin, clindamycin, minocycline, vancomycin, fusidic acid, ofloxacin, and nadifloxacin). The concentrations required to inhibit 50% of the strains (MIC(50)) of all these antimicrobial agents was extremely stable and ranged at levels below 3.13 microg/ml, except for gentamicin; in contrast, the MIC(90) was not uniform. The MIC(90) of vancomycin, fusidic acid, and nadifloxacin was very low and stable. No strain was resistant to vancomycin. The incidence of MRSA was 10%-20%.