Nanocomposit of multi-walled carbon nanotubes and tin oxide (MWCNTs/SnO2) was used as an anode material in Microbial fuel cells (MFCs). The anode was constructed by coating of the nanocomposits on the glassy carbon electrode (GCE). The MWCNTs-SnO2/GCE showed the highest electrochemical performance as compared to MWCNT/GCE and bare GCE anodes. MWCNTs-SnO2/GCE, MWCNT/GCE and bare GCE anodes showed maximum power densities of 1421 mWm−2, 699 mW m−2 and 457 mW m−2, respectively. The electrodes were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The electrochemical properties of the MFC have been investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). High conductivity and large unique surface area extremely enhanced the charge transfer efficiency and the growth of bacterial biofilm on the electrode surface in MFC. Comparison of the power density of the proposed MFC with the other one in the literature showed that the MWCNTs/SnO2 nanocomposit was a desirable anode material for the MFCs.