ABSTRACT: Biofilm formation and hemolytic activity are closely related to the pathogenesis of Staphylococcus aureus infections. Herein, we show that lapatinib (12.5 μM) significantly inhibits biofilm formation and hemolytic activity of both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolates. Using quantitative reverse transcription PCR, we found that the RNA levels of transcriptional regulatory genes (RNAIII, agrA, agrC, saeR, and saeS), biofilm-formation-related genes (atl, cidA, clfA, clfB, and icaA), and virulence-related genes (cap5A, hla, hld, hlg, lukDE, lukpvl-S, staphopain B, alpha-3 PSM, beta PSM, and de