A series of N(2),N(4)-disubstituted quinazoline-2,4-diamines has been synthesized and tested against multidrug resistant Staphylococcus aureus. A structure-activity and structure-property relationship study was conducted to identify new hit compounds. This study led to the identification of N(2),N(4)-disubstituted quinazoline-2,4-diamines with minimum inhibitory concentrations (MICs) in the low micromolar range in addition to favorable physicochemical properties. Testing of biological activity revealed limited potential for resistance to these agents, low toxicity, and highly effective in vivo activity, even with low dosing regimens. Collectively, these characteristics make this compound series a suitable platform for future development of antibacterial agents.