Ethanol is a renewable resource of energy and is potentially cleaner alternative to fossil fuels. The search for alternative and renewable source of fuels especially for transportation has taking a centre stage across the world due to its ecofriendliness (minimize emission of greenhouse gases) and environmental sustainability. Cellulosic plant materials like fruit wastes and crop residuesare mainly composed of cellulose, hemicellulose and lignin, the cheapest source of fermentable sugars. They are attractive feed stocks for bioethanol production due to their cost effectiveness, renewability and abundance. The pretreatment methods can significantly enhance hydrolysis of biomass and thus enhance ethanol production. The present review focuses on various pretreatment methods based on composition of lignocellulosic biomass and production of ethanol by fermentation.