Greenhouse gas (GHG) emissions are becoming increasingly concerning, with problems arising globally for the environment. There is an urgent need to have a clear picture of what is happening to the environment due to the GHGs emission from solid waste management (SWM). Thus, a GHG emissions inventory for SWM is needed to allow for the monitoring and control of further harmful emissions, allowing local authorities to provide solutions. This study aims to evaluate the processes and core parameters in SWM that contribute to emissions, and then calculate the GHG emissions for all processes. It specifically covers the solid waste management of eleven municipalities in Selangor, Malaysia, which aim to achieve sustainable city status. All related data and information in this study have been obtained from KDEB Waste Management, a company that manages waste for all twelve municipalities in Selangor State, along with secondary data that was found in previous studies. The data were analyzed using the LCA method in OpenLCA software. The results of this study suggest that the collection and transport processes contributed to the highest emissions and that additional low-carbon processes in solid waste management may help to reduce emissions. The research also recommends a thorough approach when selecting a suitable GHG-calculating tool.