In this study, the effect of sodium tungstate on aerobic digestion of waste sewage sludge (WSS) was investigated. Interestingly, enhanced methane production was found according to the increased concentration of sodium tungstate to WSS. Acidogenesis stage was influenced by sodium tungstate because the amount of acetate decreased whereas that of isobutyrate increased during the anaerobic digestion of WSS supplemented with sodium tungstate. Since acetate consumed with time during the anaerobic digestion of WSS, the pH of WSS increased in the presence of sodium tungstate. The analyses of methanogenesis via acetoclastic and hydrogentrophic methanogens indicate that methane production from acetate was high in the WSS with sodium tungstate. In addition, the addition of sodium tungstate to the initial fresh WSS did not enhance methane production from acetate; therefore, sodium tungstate may increase the number of acetoclastic methanogens rather than promote the catalytic reaction related to the methane production. The analyses of archaeal population supported that acetoclastic methanogens (mostly Methanosaeta) increased from 3.02% to 31.20% in the presence of sodium tungstate. Furthermore, the addition of sodium tungstate enhanced the growth of Methanosarcina acetivorans C2A. Taken together, sodium tungstate increases methane production via the anaerobic digestion of WSS by increasing the activity of acetoclastic methanogenesis.