Technology of microbial fuel cells allowing for the direct production of electricity from biodegradable materials can provide only energy production, but also wastewater treatment. This technology is seen as supporting of the traditional wastewater treatment. One of the problems with microbial fuel cells is a low current density of those energy sources. Nonetheless, it is possible to increase the current density by using the catalyst for electrodes (anode and cathode). The possibility of wastewater treatment using the Ni-Co alloy as catalyst for single chamber microbial fuel cells is presented in this paper. The studies have included measurements of H₂O₂ reduction on Ni-Co catalyst, power of cell and current density and also COD reduction. The reduction time for COD with the use of single chamber microbial fuel cell with Ni-Co cathode is similar to the reduction time with aeration. In analysed cell was obtained cell power of 13 mW, and current density of 0.21 mA/cm². The possibility of using the Ni-Co alloy as catalyst for cathode of single chamber microbial fuel cells is presented in this paper.