-In recent years, Anaerobic Digestion (AD) has become an important technological alternative for the management of municipal biowaste (MBW) for both pollution control and obtaining renewable energy such as methane. One of the factors that most affects the AD of MBW is the particle size, particularly in the hydrolysis and lag phases, this last being in general the limiting stage of solid waste AD. This research evaluated on a laboratory scale the AD of MBW by evaluating Biochemical Methane Potential (BMP) at a temperature of 30 °C during 30 days and the influence of particle size. The particle sizes ranged between < 2 mm to 12.5 mm. Along the study, better results were observed for particle sizes < 2 mm, obtaining productions of methane and electrical energy of 128 mL gVS -1 and 2960.4 kWh week -1 respectively (19% higher than in reactors with larger particles), thus indicating lower costs for design and maintenance.