A series of ruthenium(II) bis(2,2′-bipyridyl) complexes containing N-phenyl-substituted diazafluorenes (Ru-C₁, Ru-C₆, Ru-C₇ and Ru-F) was synthesized and their potential antibacterial activity against methicillin resistant Staphylococcus aureus (MRSA) was investigated. The Ru-C₇ complex showed significant improvement in both minimum inhibitory concentration (MIC, 6.25 μg mL⁻¹) and minimum bactericidal concentration (MBC, 25 μg mL⁻¹) towards MRSA when compared with those of methicillin (positive control) (MIC = 25 μg mL⁻¹ and MBC = 100 μg mL⁻¹). The Ru-C₇ complex possessed much stronger antibacterial effects than the Ru-C₆ complex (MIC, 25 μg mL⁻¹, MBC, >100 μg mL⁻¹). Both Ru-C₆ and Ru-C₇ complexes were also demonstrated to be biologically safe when tested on normal human skin keratinocytes.