“Bacterial Interactions with Antimony†Antimony (Sb) is a metalloid that shares chemical and toxicological properties with arsenic. Sb is found naturally in the environment at very low concentrations, although may be a dangerous component in polluted water and soil. The toxicity of Sb depends on its oxidation state, being more toxic Sb(III) than Sb(V). The mechanism of toxicity of Sb(III) is based on its affinity for thiol groups and its ability to generate oxidative stress. Sb(III) derivatives are considered as potential carcinogen agents in humans. Sb(III) is taken up by prokaryotic and eukaryotic cells through glycerol transporters, such as aquaglyceroporins. Some bacterial species have developed resistance systems against Sb that are based generally on membrane proteins able to extrude Sb(III) from the cell cytoplasm. Sb has a biogeochemical cycle in the planet that involves redox transformations and methylation reactions. In this work we briefly summarize the information related with the bacterial interactions with antimony.