In April 1999, a 63-year-old woman with MRSA bacteremia (MIC <1 µg/mL) was transferred from a long-term-care facility to an Illinois hospital (hospital A). The patient had a history of frequent hospitalizations for complications of hemodialysis-dependent, end-stage renal disease, and intravascular access, including two failed arteriovenous grafts, multiple central venous catheter-associated infections, and intermittent receipt of vancomycin therapy through June 1998. Thirteen days after hospital admission and 25 days after initiating vancomycin therapy (median vancomycin serum concentration = 12.7 µg/mL; range: 12.1 µg/mL-20.9 µg/mL), a culture from her blood grew S. aureus with an MIC of 4 µg/mL; the blood culture was tested using the Vitek® system (bioMerieux; Hazelwood, Missouri).* Three subsequent blood specimens drawn within the next 3 days grew S. aureus with MICs of 8 µg/mL on confirmatory testing. The isolates, identical by pulsed-field gel electrophoresis, were resistant to penicillin, oxacillin, clindamycin, erythromycin, ciprofloxacin, and rifampin but susceptible to trimethoprim-sulfamethoxazole, tetracycline, gentamicin, and had intermediate susceptibility to chloramphenicol. No VISA strains were recovered from other body sites. An echocardiogram demonstrated a mitral valve vegetation but the patient declined surgical intervention. Despite treatment with intravenous vancomycin, rifampin, and tobramycin, the patient died 10 days after the first VISA blood specimen was drawn; the cause of death was endocarditis.