The use of bacteria for cancer therapy, whichwas proposed many years ago, was not recognized as apotential therapeutic strategy until recently. Technologicaladvances and updated knowledge have enabled the geneticengineering of bacteria for their safe and effective applicationin the treatment of cancer. The efficacy of radiotherapydepends mainly on tissue oxygen levels, and low oxygenconcentrations in necrotic and hypoxic regions are a commoncause of treatment failure. In addition, the distributionof a drug is important for the therapeutic effect of chemotherapy,and the poor vasculature in tumors impairs drugdelivery, limiting the efficacy of a drug, especially in necroticand hypoxic regions. Bacteria-mediated cancer therapy(BMCT) relies on facultative anaerobes that can survivein well or poorly oxygenated regions, and it therefore improvesthe therapeutic efficacy drug distribution throughoutthe tumor mass. Since the mid-1990s, the number of publishedbacterial therapy papers has increased rapidly, with adoubling time of 2.5 years in which the use of Salmonellaincreased significantly. BMCT is being reevaluated to overcomesome of the drawbacks of conventional therapies. This review focuses on Salmonella-mediated cancer therapyas the most widely used type of BMCT.2.