The rise in oil price triggered the exploration and enhancement of various renewable energy sources. Producing biogas from organic waste is not only providing a clean sustainable indigenous fuel to the number of on-farm digesters in Europe, but also reducing the ecological and environmental deterioration. The lignocellulosic substrates are not completely biodegraded in anaerobic digesters operating at commercial scale due to their complex physical and chemical structure, which result in meager energy recovery in terms of methane yield. The focus of this study is to investigate the effect of pre-treatments: thermal, thermo-chemical and chemical pre-treatments on the biogas and methane potential of dewatered pig manure. A laboratory scale batch digester is used for these pre-treatments at different temperature range (25 degrees C-150 degrees C). Results showed that thermo-chemical pretreatment has high effect on biogas and methane potential in the temperature range (25-100 degrees C). Maximum enhancement is observed at 70 degrees C with increase of 78% biogas and 60% methane production. Thermal pretreatment also showed enhancement in the temperature range (50-10 degrees C), with maximum enhancement at 100 degrees C having 28% biogas and 25% methane increase. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.