Xenobiotic compounds are chemical compounds that are produced by man and by the environment also but in very low concentrations. If these compounds are getting accumulated in the environment, then they will reach toxic concentrations and gives harmful effectson our environment. We need to reduceits direct or indirect use in our day-to-day life. We should also think about its degradation so that it won’t get accumulated in our environment. For doing this we should first know about it, its chemical nature, its degradability according to its chemical composition, its biodegradation by different microorganisms and the metabolic pathways within the microorganism, and the metabolic complications which arise because of the complexity of the compounds.All the above information will help us to boost the existing metabolic pathways of microorganisms and also to genetically modify the metabolic pathways to keep our environment somewhat clean and healthy. here we are going to discuss all the related information like-what is the basic meaning of xenobiotic compounds, their effect on metabolic pathways of a microorganism according to its chemical composition like the presence of halogens, cyclic groups, branched-chain, etc., hazards from xenobiotic compounds like toxicity, carcinogenicity, etc. After knowing its chemical composition and hazardous effect we will discuss the bacteria which are involved in the biodegradation of these compounds and the general features of its biodegradation, then we will discuss the co-metabolism and gratuitous metabolism of these compounds by microorganisms this information on co-metabolism will help us to boost the metabolic pathways involved, then we will discuss little the origin and capacity to degrade xenobiotic compounds because of mutation and plasmid transfer among the bacteria. After gathering all of this information we will discuss the practical approaches to degrade these xenobiotic compoundslike using mixed culture etc.