The emission of methane from dumpsites remains a significant source of global environmental pollution concern. This study investigated the physical composition and volume of municipal solid waste at the central dumpsite, Egbedi, Osogbo metropolis. The volume of landfill gas and concentration of methane gas that will be produced via anaerobic digestion over a specified period towards the possibility of energy recovery were also estimated. Results from the characterization of the municipal solid waste revealed that organic materials constitute the highest fraction (35.71 %). The energy content of the organic material was determined to be 21,582.8 kJ/kg. The methane generation potential from 2017 to 2025 was estimated to be around 41,125 tonnes by employing the method proposed by the Intergovernmental Panel on Climate Change (IPCC). Methane gas emitted can be harvested and utilized as a renewable source of energy thereby mitigating pollution environmental occasioned by the release of methane into the atmosphere from dumpsites most especially from developing countries towards ensuring a sustainable city. • Waste management is a challenge in developing world. • Municipal solid wastes in developing countries have a high organic component. • Methane from landfill gas is a significant contributor to global warming.