The sensitivity of Staphylococcus aureus (S. aureus) to methicillin, penicillin, gentamicin, erythromycin, ciprofloxacin, fusidic acid and mupirocin was tested in 1152 clinical isolates from nine hospital microbiology departments. In all cases standard methods for culture and sensitivity were employed using either the Stokes' or a modified Stokes' method for susceptibility testing. The isolates were recovered from 1150 patients (606 men, 544 women; mean age: 41 years) and only those deemed relevant to the patient's clinical condition were included. Of the total 1152 isolates, 454 were regarded as hospital acquired, 506 were community acquired and the source of the remaining 192 isolates was unknown. The overall percentages of S. aureus sensitive to the tested antibiotics were as follows: methicillin 85%, penicillin 8%, gentamicin 89%, ciprofloxacin 85%, erythromycin 80%, fusidic acid 96%, mupirocin 98%. The sensitivity of the methicillin resistant strains to the other antibiotics tested was generally low except for fusidic acid and mupirocin, both of which retain good activity against methicillin resistant S. aureus (MRSA).