BACKGROUND:Pesticides are used to control various pests of agricultural crops worldwide.Despite their agricultural benefits,pesticides are often considered a serious threat to the environment because of their persistence.Pyrethroids are synthetic derivates of pyrethrins,which are natural organic insecticides procured from the flowers of Chrysanthemum cinerariaefolium and C.coccineum.Pyrethroids are classified into two groups-class Ⅰ and class Ⅱ-based on their toxicity and physical properties.These pyrethroids are now used in many synthetic insecticides and are highly specific against insects;they are generally used against mosquitoes.The prominent site of insecticidal action of pyrethroids is the voltage-sensitive sodium channels.METHODS and RESULTS:Pyrethroids are found to be stable,and they persist in the environment for a long period.This article provides an overview of the different classes,structure,and insecticidal properties of pyrethroid.Furthermore,the toxicity of pyrethroids is also discussed with emphasis on bioremediation to alleviate pollution.CONCLUSIONS:The article focuses on various microorganisms used in the degradation of pyrethroids,the molecular basis of degradation,and the role of carboxylesterase enzymes and genes in the detoxification of pyrethroid.