A novel structural class of antibacterials, 2-(1H-indol-3-yl)quinolines, effective against methicillin-resistant Staphylococcus aureus (MRSA), was discovered from a combinatorial library. A structure-activity relationship (SAR) study was conducted to determine the pharmacophore and increase the potency of these compounds. Compounds were prepared that had minimum inhibitory concentrations (MICs) < 1.0 <mu>g/mL against MRSA and retained activity against two strains of glycopeptide intermediate-resistant S. aureus (GISA). (C) 2000 Elsevier Science Ltd. All rights reserved.