The organic fraction of municipal solid waste can be a significant energy source for renewable energy generation. The total production of municipal solid waste in Turkey was 25×106 tones per year. Anaerobic digestion (AD) process may be a solution to the problems of energy demand and waste management since it provides biomethanation along with waste stabilization. AD can be operated in single or two phase configurations. Two-phase processes have some advantages over one phase systems in terms of selection of microorganisms, process efficiency, and reactor size. In this study, biochemical methane production experiments were performed in order to investigate whether phase separation enhanced the efficiency of methanogenic activity or not. The performances were compared in terms of total chemical oxygen demand (tCOD) and volatile solids (VS) reductions, and cumulative gas production. The experimental results indicated that 10% and 23% increases in tCOD and VS removals were achieved, respectively, by phase separation. The acetic and propionic acids were not detected in the reactors, which was an indication of successful methanization.