The hydrogen production from biomass gasification needs to be improved through investigation of the operating parameters and thermodynamic efficiencies (energy and exergy). A comprehensive study is conducted to predict H-2 production with a gasifier using a quantity of 14.5 kg/s from biomass (wood sawdust) and an amount of 6.3 kg/s of steam at 500 K and evaluate system performance through energy and exergy efficiencies for hydrogen production from biomass. The gasification process takes place in a temperature range of 950-1500K and steam-biomass ratio of 0.17-0.51. The results indicate that an improvement in exergy efficiency from 33 to 37% is possible during hydrogen production only. It becomes more sensitive if the temperature goes beyond 1000K. In this regard, the exergy efficiency increases from 42 to 47% when all of the product gases are taken in consideration and from 47 to 52% when all of the products from the gasification process are taken in consideration. Over a range of gasifier temperatures, the gasification ratio is 97-105g H-2/kg of biomass while hydrogen yield reaches 1.5 kg/s for the studied biomass. (C) 2010 Elsevier B.V. All rights reserved.