This study was undertaken to investigate the in-vitro susceptibility of Staphylococcus aureus strains to ciprofloxacin and moxifloxacin. A total of 440 strains isolated from various clinical specimens were included in the study. The susceptibility tests were performed by agar dilution method according to the NCCLS criteria. Strains with MIC value of ≥ 4 mg/L and ≤ 1 mg/L were interpreted as resistant and susceptible to ciprofloxacin, respectively. Twenty-seven (14%) of 196 methicillin-susceptible S. aureus (MSSA) strains and 239 (98%) of 244 methicillin-resistant S. aureus (MRSA) strains were resistant to ciprofloxacin. MIC50 and MIC90 values of 27 ciprofloxacin-resistant MSSA strains for moxifloxacin were 0.25 mg/L and 4 mg/L, respectively. MIC50 and MIC90 values of ciprofloxacin-susceptible MSSA strains for moxifloxacin were ≤ 0.125 mg/L and 0.250 mg/L, respectively. Moxifloxacin was 4-fold more active than ciprofloxacin against MSSA strains. There was no difference between these two quinolones against MRSA strains (MIC90s: ≥ 16 mg/L). Moxifloxacin might be a good alternative in the treatment of infections caused by MSSA strains.