Open burning of municipal solid waste (MSW) remains one of the least addressed yet significant sources of greenhouse gas (GHG) emissions in developing countries. The practice not only contributes to global climate change but also poses serious threats to public health, air quality, and urban liveability. This project investigates the extent and mitigation potential of GHG emissions resulting from open waste burning in two rapidly urbanizing regions of South Asia, Kathmandu Valley (KV), Nepal, and Dhaka City, Bangladesh. These two cities represent contrasting geophysical and socio-economic contexts: KV is in the foothills of the Himalayas, while Dhaka lies within the Ganges Delta’s lowlands. Both areas face mounting challenges in waste management due to urban expansion, inadequate infrastructure, and limited enforcement of waste disposal regulations. The study employs a comprehensive methodological framework integrating household surveys, transect walks, and real-world field experiments to quantify the magnitude of open waste burning and its associated GHG emissions. A total of 385 households in KV and 397 households in Dhaka City representing low, middle, and high socio-economic strata were surveyed alongside 50 institutional and 50 commercial entities in each city. Field and laboratory experiments were conducted to determine key parameters such as the waste combustible fraction (WCF), burning oxidation factor, and emission factors (EFs) for carbon dioxide (CO₂). Likewise, EF for methane (CH₄) and nitrous oxide (N₂O) were obtained from the literature. The methods followed the established IPCC guidelines.