In the present study the catalytic steam gasification of MSW to produce hydrogen-rich gas or syngas (H-2 + CO) with calcined dolomite as a catalyst in a bench-scale downstream fixed bed reactor was investigated. The influence of the catalyst and reactor temperature on yield and product composition was studied at the temperature range of 750-950 degrees C, with a steam to MSW ratio of 0.77, for weight hourly space velocity of 1.29 h(-1). Over the ranges of experimental conditions examined, calcined dolomite revealed better catalytic performance, at the presence of steam, tar was completely decomposed as temperature increases from 850 to 950 degrees C. Higher temperature resulted in more H-2 and CO production, higher carbon conversion efficiency and dry gas yield. The highest H-2 content of 53.29 mol%, and the highest H-2 yield of 38.60 mol H-2/kg MSW were observed at the highest temperature level of 950 degrees C, while, the maximum H-2 Yield potential reached 70.14 mol H-2/kg dry MSW at 900 degrees C. Syngas produced by catalytic steam gasification of MSW varied in the range of 36.35-70.21 mol%. The char had a highest ash content of 84.01% at 950 degrees C, and negligible hydrogen, nitrogen and sulphur contents. Crown Copyright (C) 2008 Published by Elsevier Ltd on behalf of international Association for Hydrogen Energy. All rights reserved.