The in vitro activity of telavancin was tested against 620 gram-positive isolates. For staphylococci, MICs at which 50 and 90% of isolates were inhibited (MIC50 and MIC90) were both 0.25 mu g/ml, irrespective of methicillin resistance. MIC50 and MIC90 were 0.25 and 0.5 mu g/ml for vancomycin-susceptible enterococci and 1 and 2 mu g/ml for vancomycin-resistant enterococci, respectively. Streptococcus pneumoniae, group A and B beta-hemolytic streptococci, and viridans streptococci were inhibited by <= 0.12 mu g/ml.