To enhance the production of biohydrogen from biomass, various pretreatment methods play important role. In this study, effect of microwave irradiation on the culture was studied on biohydrogen production from Benincasa hispida (Petha) solid waste at different powers for a fixed interval of time. The highest power studied was 800 W with a frequency of 2450 MHz. The amount of soluble sugars found in the waste was 13.9 mg/L having the chemical oxygen demand (COD) of 3000 mg/L. Studies have been performed in batch reactors using mixed consortia and results were also compared with the reactor operated at the normal conditions i.e. without any inoculum pretreatment. Maximum hydrogen produced was 14 mmol H-2 per mol of soluble sugar consumed in the reactor in which the inoculum was exposed to 320 W of microwave for 5 min. SEM analysis of this microwave pretreated culture was done. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.