Detoxification by overliming was applied to enhance biogas production from an industrial baker's yeast production wastewater. Various operational parameters affecting the detoxification, i.e., temperature, duration time, and pH, were studied for improvement of biogas production. Overliming was carried out at different pH levels (9 to 12) and temperatures (20 to 60 degrees C) for different periods of time (0 to 12 h). Then, the detoxified wastewaters were subjected to anaerobic digestion. The maximum biogas production of 425 ml CH4/g COD, and the maximum yield of methane production of 3.06 l CH4/l wastewater were achieved under optimum conditions for overliming of wastewater.