Flavin-containing monooxygenases (FMOs) are an important monooxygenase system present in living organisms starting from eukaryotes to human beings. They are involved in catalysing wide variety of oxygenation reactions including bioremediation process. The central reaction in these enzymes is always the formation of a peroxyflavin intermediate by reaction of reduced flavin with molecular oxygen. The microenvironment of the peroxyflavin regulates the reactive character of the peroxyflavin. Utilizing this aspect of the biology, chemremediation of aromatic halogenated phenols have been initiated and achieved using flavinium perchlorate salt as catalyst in 38 % yield. The flavinium perchlorate during the reaction gets converted to peroxyflavin with H2O2. This method will be useful in the removal of halogens from aromatic halogenated phenols.