Antibiotic susceptibility testing in 231 strains of S. aureus isolated from patients highly exposed to the nosocomial risk and from patients treated in ambulatories for staphylococcal infections revealed significant discrepancies in respect to the incidence of multiple resistant strains and dispersion of resistance phenotypes. MRSA incidence rose to 58-85% in hospital boards, that indicated an "alarm state" which requests the supply of the efficient antibiotic. The 27.18% of MRSA between the strains isolated in ambulatories points to the risk of spreading this strains abroad the community and into the hospital boards and requests the monitoring of the chemotherapy in such of health carry units and of the antibiotic "automedication".