The issue of heavy metals (HMs) contamination has become a matter of significant international concern. As a result, various techniques employed by biological systems to eliminate HMs are being examined. Specific HMs, such as cadmium, zinc, nickel, copper, and cobalt, are necessary for the physiological functions of both symbiotic and non-symbiotic nitrogen-fixing bacteria (NFB) when present in minor amounts. However, elevated levels of HM concentrations can impair the functioning of NFB and their symbiotic relationship. The present investigation focuses on how the NFB, resists the HMs toxicity and increases plant growth to assist in accomplishing crop cultivation in metal-contaminated locations. Numerous mechanisms were reviewed for HMs resistance such as organic ligands and thiols which annoy the metal ions constructing a complex and blocking cell impairment. This review summarizes that soil inoculation with HMs-resistant NFB reflects numerous beneficial effects in agricultural systems, therefore its application is considered a bioremediating tools that have economic and ecological importance. In addition, the current review discussed the role of NFB in reducing the toxic impacts of HMs on plant life.