Incorporation of a bicyclo[1.1.1]pent-1-yl group at the N-1 position of quinolone antibacterial agents affords compounds with potent activity. One of these analogs, U-87947E, exhibits enhanced activity relative to that of ciprofloxacin against gram-positive aerobic bacteria and anaerobic organisms. Time-kill kinetic studies reveal that U-87947E is exquisitely bactericidal against ciprofloxacin-resistant Staphylococcus aureus.