AbstractInfectious diseases associated with antimicrobial resistance are considered to represent an important public health problem. In this regard, the mushroom Agaricus blazei Murrill contains several bioactive substances that promote significant functional properties, among them, antimicrobial activity, which has attracted the interest of the scientific community. Thus, the aim of this study was to determine whether evidence of the antimicrobial action of A. blazei has been reported in the literature. In this integrative review, manuscripts held in research databases available online were examined with a view to answering the question “Does the mushroom A. blazei exert antimicrobial activity against Gram-negative and/or Gram-positive bacteria?” Only eight scientific articles that have addressed the antimicrobial properties of A. blazei, in vitro and in vivo, were found, all characterized as pre-clinical, i.e., with level VII evidence. Most authors have found that the A. blazei extract promotes an antimicrobial effect against peritonitis, as well as deadly oral infections, especially those caused by Gram-positive bacteria. However, the scientific data currently available are not sufficient to verify the antimicrobial aspect of the mushroom A. blazei and thus further investigation is required.