BACKGROUND: Yeast, Saccharomyces cerevisiae, is quite safe, easily available, rapid-growing and one of few microorganisms that can metabolize complex organic materials. The effect of different anode materials such as carbon cloth (CC), carbon paper (CP), Teflon-treated carbon paper (CP-T), and porous carbon plate (PCP) on the performance of mediatorless yeast, S. cerevisiae-based MFC was investigated to explore some issues that are affecting the performance. RESULTS: The variation in the open circuit voltage (OCV), and power generation for CC, CP and CP-T, were explained by the different areal densities of the yeast cells that adhered to the anode surface. The highest power was obtained using the CP anode. On the other hand, the PCP anode with dense adhesion of the yeast cells, which was expected to give the highest performance; showed the lowest performance. Modifying the PCP surface with a thin nanolayer of cobalt significantly increased the performance over fifty times. CONCLUSION: The performance of a mediatorless yeast-based microbial fuel cell, i.e. OCV and current density, was affected by the adhesion density of the yeast cell on the electrode surface. However, it was not the only factor affecting the cell performance. The yeast cell adhesion on the anode surface was dependent on the carbon materials. The improvement of the interfacial electron transfer between the anode and yeast cells is key for the development of yeast based mediatorless MFCs. (C) 2017 Society of Chemical Industry