Lignocellulosic biomass can be utilised to produce ethanol. There a are two processes involved in the conversion: hydrolysis of cellulose in the cellulosic biomass to produce reducing sugars, and fermentation of the sugars to bioethanol. For this, pretreatments for lignocellulosic materials are required. The goal to any pretreatments is to alter or remove the structural and compositional impediments to hydrolysis and to increase the yields of fermentable sugar. In this work is made a review of the physical or chemical pretreatment methods that could be used to produce bioethanol from cellulosic materials.