This study was conducted on twenty-eight men at Halley Base, Antarctica, in total physical isolation from all other human contact from beginning March to end December 1983. Aims of study: observe <i>S. aureus</i> carriage in this community; monitor effects on carriage of topical antibacterials. Initially, weekly nasal, axillary and perineal swabs taken. From week 24 throat swabs taken from known nasal carriers. Two courses of antibacterials given to all subjects, regardless of carrier status. Two further courses given to known carriers. Eight subjects consistently carried own phage type throughout study, despite application of antibacterials. Eradication appeared successful in two, possibly three individuals, but after significant interval (39 weeks in one) <i>S. aureus</i> found of phage type either not isolated before in study, or not found for prolonged period. May reflect inadequacy of conventional sampling methods. <i>S. aureus</i> in throat of nine of twelve nasal carriers. No consistent skin carriers. Seven subjects intermittent nasal carriers. Four probably acquired strain from consistent carriers. Approximately 90% of stored isolates revived for phage on return to UK. Two consistent carriers and one intermittent carrier yielded non-typable strains. Alternative typing method developed. All phage types indistinguishable by polyacrylamide gel electrophoresis (PAGE) of whole cell extracts. Insufficient protein in supernatants for PAGE. Western Blotting of supernatants using normal human plasma as anti-staphylococcal antibody source distinguished between different phage types, but non-typable strains still indistinguishable. Conclusions: 1) Individuals' carrier status stable over many months. Living in proximity to persistent carriers, some individuals never gave positive swab. 2) Throat may be significant carriage site. 3) Topical antibacterial application unlikely to eradicate <i>S. aureus</i> from nose, particularly in persistent carriers. 4) Apparent eradication may represent suppression. 5) Western Blotting of culture supernatants may provide alternative typing method, also information on strains of direct clinical significance.