Bioremediation is a process that entails using microorganisms to convert hazardous waste into safe waste; therefore, this is a suitable, cost-effective, and eco-friendly technique for waste management and restoration of the natural balance of the environment. It is necessary because of increasing contamination with petroleum hydrocarbons, heavy metals, and synthetic organic chemicals for large-scale habitat restoration. Pollutants can be chemical, biological, and even physical entities that cause an adverse effect on air, water, soil, or living organisms. Heavy metals as chemical pollutants, pesticides, hydrocarbons, and industrial chemicals are harmful; they are nonbiodegradable and have adverse effects on both humans and animals. The most common class of organisms, and the most widely studied for bioremediation, are bacteria because of their versatile nature and their ability to metabolically degrade a variety of xenobiotics. The number of bacterial species varies according to the degree of oxygen availability in an ecosystem such as Pseudomonas species that can degrade hydrocarbons and PCBs. Geobacter spp. can be used to remediate anaerobic conditions with inorganic ions of nitrate, sulfate, and other heavy metals. Genetically engineered bioremediation bacteria can target and degrade environmental pollutants due to bioremediation advances in genetic engineering.