In an attempt to identify risk factors forStaphylococcus aureus septicemia, 136 consecutive HIV-infected patients were investigated for the presence of nasopharyngeal colonization withStaphylococcus aureus and subsequentStaphylococcus aureus infection. Sixty of 136 (44.1 %) HIV-infected patients had staphylococci which were detected in the nasopharynx on initial culture compared to 12 of 39 (30.8 %) patients with chronic diseases and 11 of 47 (23.4 %) healthy hospital staff. Another 12 HIV-infected subjects proved to beStaphylococcus aureus carriers on follow-up cultures. Patients with full-blown AIDS had a higher carriage rate compared to subjects who were only HIV-positive (p<0.05), indicating="">Staphylococcus aureus colonized patients were more severely ill. Eight patients withStaphylococcus aureus septicemia were observed, all of whom were carriers; no septicemia occurred in the non-colonized patients (p<0.01). colonized="" patients="" with="" neutropenia="">< 1000/µl)="" were="" significantly="" more="" likely="" to="" develop="" septicemia=""><0.01). nasopharyngeal="" colonization="">Staphylococcus aureus and the presence of an indwelling catheter were established to be factors that help identify patients at risk of acquiring subsequentStaphylococcus aureus infection.