Abstract：The end of the "golden age" of antibiotic discovery along with the growing antibiotic resistance left us a dramatic shortage of new drugs to prevent and cure drug-resistant pathogens. This makes it a new alternative approach to screen antibacterial activity from existing non-antimicrobial drugs. Recent studies show that gallium nitrate, a compound approved for treatment of hypercalcemia by US FDA, has potent antibacterial activities. Unlike classical antibiotics, the pharmacological property of gallium lies on its chemical mimicry, which can cause malfunction and disruption of enzymes using iron as a co-factor, and thus interfere with bacterial metabolism. Gallium has shown bactericidal activity against many pathogens, including multidrug-resistant ones, both in vitro and in vivo. Some gallium-containing regimens are expected to be developed as non-traditional and potentially effective anti-infective agents that help combat multidrug-resistant bacterial infections.