Municipal solid waste management (MSWM) poses a critical obstacle in rapidly urbanizing cities, particularly in developing countries like Nepal. This study employs the Life cycle assessment (LCA) approach for evaluating the environmental impacts to identify best performing scenario from five different waste management scenarios in Lalitpur Nepal. The study quantifies 12 impact categories (e.g. global warming potential, eutrophication potential, ecotoxicity potential, and human toxicity potential) and two damage categories (human health and ecosystem quality) using SimaPro software and the ReCiPe 2016 impact assessment method. The results indicate that the current landfill-dominated waste management has the highest global warming potential (2052.13 kg CO2 eq/ton) in scenario 1 due to uncontrolled methane emission, in contrast, scenario 5 consists of the integration of recycling, biological treatment and incineration of waste, achieves the least global warming potential (46.17 kg CO2 eq/ton) through material recovery and energy recovery. However, incineration-dominated scenarios lead to an increase in human toxicity and ecotoxicity due to heavy metal emissions. This study also found that enhancing recycling rates significantly reduces the environmental burden. Furthermore, the study highlights the necessity for policymakers in Nepal and similar region to adopt integrated waste management that integrate biological treatment and thermal treatment of waste that offers most environmentally friendly path. The policies should focus on source separation and recycling of waste and enforce strict landfill regulation that has leachate treatment and landfill gas recovery system.