Energy generation from dairy industry wastewater was investigated using a dual chambered Microbial Fuel Cell by aerobic and anaerobic anodic metabolism, operating with initial COD concentration of 1600 mg/L and anolyte pH of 7 produced highest power density of 192, 161 mW/m(2) and volumetric power of 3.2, 2.7 W/m(3) with COD removal efficiency of 91% and 90%, respectively. The columbic efficiency was 3.7-folds lower for aerobic metabolism compared to anaerobic metabolism with 17.17%. Effect of operating parameters such as anolyte pH and COD concentration on MFC performance was also evaluated. Anaerobic metabolism operated with COD concentration of 1600 mg/L and anolyte pH 7 showed best performances. Biofilm formation by inherent microbes of wastewater on anode was visualized by instrumental techniques. Milk processing operation runs almost through the year, hence MFC utilizing dairy industry wastewater would be a sustainable and reliable source of bio-energy generation. (C) 2013 Elsevier Ltd. All rights reserved.