This study was carried out to assess the impact of organic loading rate (OLR) on the performance of mesophilic anaerobic baffled reactor (ABR) for H-2 production from a co-digestion of municipal food waste and kitchen wastewater. The reactor was operated at different organic loading rates (OLRs) of 29,36 and 47 g CODtotal/Ld. The hydraulic retention time (HRT) was kept constant at 1.6 d. The results showed that increasing the OLR from 29 to 36 g CODtotal/Ld, leads to a significant (p square 0.01) drop in the H-2 production from 6.0 +/- 0.5 to 5.4 +/- 1.04 L H-2/d, respectively. However, the H-2 production remained at the same level of 5.3 +/- 1.04 L H-2/d at increasing the OLR from 36 to 47 g CODtotal/Ld. The H-2 generation was mainly due to conversion of COD (57%) and carbohydrate (81%). Protein and lipids conversion represents only 23.3% and 4.1% respectively for H-2 production. (C) 2012 Elsevier Ltd. All rights reserved.