With an increasing awareness about adverse effects of pollutants on living organisms, reclamation or remediation of environment contaminated with hazardous pollutants has become a global concern.Environmental problems continue to exist for several decades, and environmental biotechnology has come up as an emerging field worldwide using microbial activity as biological treatment in solving environmental problems. Environmental pollution by solid waste, industrial effluents and various unwanted chemicals, persistent organic pollutants (POPs) like Polyaromatic hydrocarbons (PAHs), pesticides, Polychlorinated biphenyls (PCBs) etc. is a major problem. The basic knowledge on how microbial activity can be used for wastewater treatment, biofilters for odour removal, and for biodegradation of environmental organic pollutants can prove useful in pollution control. In recent research several microorganisms have been found to completely mineralize the pollutants; and genomic and proteomic studies have helped in understanding of microbial catabolic activity for removal of pollutants. Identification of genes responsible for a particular function and their multiplication using recombinant DNA technology has opened new horizons in microbial degradation of pollutants. Microbial catabolic activity depends on various environmental factors like temperature, pH, nutrients, type of microorganisms, and chemical properties of the pollutant. The implementation of aerobic as well as anaerobic microbial activities exploited for their catabolic ability to treat biodegradable waste or pollutants has become an efficient, economical and environment friendly technique. In this review, we discuss various applications of biotechnology to improve remediation the polluted environment.