Photocatalytic hydrogen production from a digested sewage sludge solubilized in hot-compressed water (573K) was investigated in order to develop a low-cost sacrifice agent for CdS-based photocatalysts from biomass. H-2 evolution occurred over a LaMnO3/CdS composite photocatalyst under Xe lamp irradiation from water containing the solubilized sewage sludge and the amount of evolved H-2 reached more than 30 mmol/g-catalyst for a 200 h-reaction; on the other hand, no H-2 was formed in the absence of the solubilized sewage sludge. The H-2 evolution rate was comparable to that when typical Na2S-Na2SO3 sacrifice agents were used, suggesting the applicability of a biomass-derived sacrifice agent for photocatalysis. Organic compounds, such as methanol and formic acid, contained in the solubilized sewage sludge are responsible for the H-2 evolution observed. (C) 2003 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.