Abstract. Lignocellulosic biomass is one of the abundant renewable bioresources on earth. Its chemical composition, i.e., lignin hinders ethanol production and commercialization. Pretreatment processes are vital for efficient separation of the complex interlinked components and enhance the availability of every component, i.e., cellulose and hemicellulose. However, for the bioethanol production, a major barrier is the removal of strong lignin component which is highly resistant to solubilization and a major inhibitor for hydrolysis of cellulose and hemicellulose. Pretreatment of biomass is necessary to make it susceptible to microorganisms, enzymes, and pathogens. Consequently, for the ethanol production, pretreatment of lignocellulosic biomass process is very costly. The initial pretreatment approaches include physical, physicochemical and biological methods. It found out that; pretreatment methods have a significant impact on efficient production of ethanol from biomass. However, extensive research is still necessary for the development of new and more efficient pretreatment processes for conversion of lignocellulosic biomass to ethanol. Present review article presents recent development on lignocellulose biomass pretreatment. We discussed the different pretreatment methods along advantages, disadvantages, and challenges for bioethanol production. This review includes benefits and drawbacks and chemical, physical, physiochemical and biological pretreatment along with existing problems. For the production of ethanol, this review will help researchers regarding selection, development and further planning of pretreatment for different lignocellulosic residues.