The use of daptomycin has increased in recent years, especially in patients with persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia following vancomycin treatment failure (10). We report a case of persistent MRSA bacteremia in a patient who received a dosage of daptomycin (12 mg/kg body weight/day) that was higher than that of the recommended standard therapy (6 mg/kg/day) (2, 10). The patient received 4 weeks of teicoplanin followed by 5 months of oral linezolid prior to daptomycin. In addition to daptomycin nonsusceptibility, the causative strain also developed heterogeneous and intermediate resistance to vancomycin, and an inverse or "seesaw" effect of daptomycin nonsusceptibility and oxacillin susceptibility was noted.