Anaerobic digestion of wastewater from jam industries was studied in a continuous reactor with different organic loading rates (OLR) and the optimum organic loading rate was 6.5 kg COD/m3/day when it was operated with three days HRT. The biodegradability of wastewater in batch experiments was about 90%. The removal efficiency of total COD and soluble COD were found to 82% and 85%, respectively. The specific methane production was 0.28 m3/kg of COD removed/day. © 2006 Elsevier Ltd. All rights reserved.