Background: Impetigo is a common bacterial infection caused by Staphylococcus aureus, and group Ab-hemolytic Streptococcus or both. Recently, S. aureus has been reported as the most frequently isolated pathogen of impetigo and the incidence of methicillin-resistant S. aureus (MRSA) among patients with impetigo has increased. Objective: To investigate the predominant microorganism and the antibiotic susceptibility of the impetigo causative pathogen. Methods: Bacterial culture and antimicrobial susceptibility testing were performed in patients with impetigo from June 2006 to May 2012. Results: Of 164 patients, bacteria were cultured from 139 patients. Among them, S. aureus was isolated from 114 (82%) patients. The others were Acinetobacter baumannii, Enterobactercloacae, Enterococcus species, Enterococcus faecium, Enterococcus faecalis, Klebsiella oxytoca, and Candida albicans. The resistance rates of S. aureus against antibiotics were as follows: penicillin, 95.6%; erythromycin, 43.9%; fusidicacid, 38.1%; clindamycin, 24.5%; gentamycin, 21%; tetracycline, 12.3%; trimethoprim-sulfamethoxazole, 0.9%; ciprofloxacin, 0%; habekacin, 0%; linezolid, 0%; teicoplanin, 0%; and vancomycin, 0%. Thirty-four (29.8%) S. aureus isolates were MRSA, and the prevalence of MRSA increased during the 6-year period. Conclusion: The most predominant pathogen in impetigo was S. aureus, which was sensitive to ciprofloxacin, habekacin, linezolid, trimethoprim-sulfamethoxazole, teicoplanin, and vancomycin. An increase in the prevalence of MRSA was observed during the 6-year period, and the effective antibiotics for MRSA were trimethoprim-sulfamethoxazole, teicoplanin and vancomycin.