Heavy metals are of great environmental concern as they are non-biodegradable, accumulate in the environment, enter into the food chain, and exert adverse effects on all living organisms including microorganisms, plants, and animals. Among different technologies, phytoremediation is a better option for reclamation of heavy metal polluted soils. Several plants including hyperaccumulators have been reported with significant remediation potential. The phytoremediation potential of these plants is also affected by microorganisms present in the plant rhizosphere. The potential role of microorganisms in phytoremediation of heavy metal contaminated sites is becoming apparent. The capability of soil microorganisms to promote the uptake and accumulation of heavy metals from soil is an important aspect of phytoremediation. The establishment of a microbiocenosis with potential to stimulate the uptake of heavy metals depends upon the microbial dynamics in the rhizospheres. Soil microorganism including plant growth-promoting rhizobacteria, P-solubilizing bacteria, mycorrhiza-helping bacteria, plant endophytic bacteria, arbuscular mycorrhizal fungi, and soil fungi have the potential to increase the phytoremediation potential of plants. Use of genetically engineered microorganisms in phytoremediation increases the plants heavy metal accumulation and widens the horizon of microbial use in the technique. The mechanism of soil microbes assisted phytoremediation include acceleration of metal mobility, immobilization, nutrient acquisition, metal detoxification, transformation, and mitigation of heavy metal stresses in plants. Soil microbes involved in biogeochemical processes operating in the rhizosphere affect the mobility and availability of heavy metal to the plant through the release of chelating agents, biosurfactants and biomethylation, metal speciation, acidification, dissolution, phosphate solubilization, and redox changes. In addition, plant-associated bacteria can also increase plant resistance to the pathogen and ensure nitrogen fixation and the production of growth regulators. This chapter presents the recent advances and applications made hitherto in understanding the functional role of plant-microbe interactions in the phytoremediation.