In this study, synergetic effect of mild acid and alkali with electron beam irradiation (EBI) on the enzymatic hydrolysis of a selected grass biomass was assessed. Biomass samples prepared by soaking with 1% H2SO4, or 1% NaOH, were exposed to 75 and 150 kGy of EBI. Water presoaked biomass was used as control. Hydrolysis of pretreated samples was carried out using cellulase (15 FPU/g biomass) for 120 h. Structural changes were studied by FTIR and XRD analyses. Reducing sugar and glucose yields from enzymatic hydrolysis were significantly higher in acid and alkali presoaked EBI exposed samples. Theoretical glucose yield showed 40% increase from control in alkali presoaked EBI exposed (150 kGy) samples. Removal of hemicellulose, decreased crystallinity and structural changes were major factors for the combined treatment effect favoring the hydrolysis. (C) 2012 Elsevier Ltd. All rights reserved.