In this paper we investigate the performance of oxygen reducing biocathodes for microbial fuel cells in relation to temperature and pH. Lower pH does likely improve biocatalytic activity and/or proton availability, and results in higher current. Lower temperature does reduce biocatalytic activity and does not reduce possible oxygen mass transfer limitations. The cathode resistance was in the same order of magnitude at pH 5 to 7 which shows that MFC energy recovery can be higher at lower pH. Overall, these results show that oxygen reducing biocathodes are robust at 660 mA per m2 at +0.15 V vs. Ag/AgCl, pH 5 and 31 °C.