Compounds containing 3-bromo-2,5-dihydro-1H-2,5-pyrroledione and indole substructures were found to have antibacterial activity against resistant strains of Staphylococcus aureus and some other Gram positive bacteria. The investigated compounds exhibit minimal inhibition concentrations (MICs) lower than those of common antibiotics like vancomycin or ciprofloxacin. Activity against multiresistant strains suggests a mechanism of action different from common antibiotics. This might be important in circumventing existing resistance mechanisms. Here we report about the antibacterial activity in an extended structure-activity relationship study.