This paper presents the results and analysis of a study conducted with the objective of investigating the cooking energy requirements in the Sri Lanka domestic sector and the environmental emissions associated with it. The study was conducted out through a sample and showed that the main household energy supply sources were biomass, liquefied petroleum gas (LPG), electricity and kerosene with electricity being used largely for water boiling in all subsectors. It was observed that the urban sector cooking is largely dominated by LPG (95% of urban households) while the rural sector cooking is confined mainly to biomass (95% of rural households). The suburban sector consists of a mixture of all the sources (LPG-70% and biomass-85% of suburban households). Similarly, LPG dominates in electrified households (76.4% of electrified households), while biomass dominates in all non-electrified households. It was found in the analysis that the highest level of gaseous emissions due to cooking activity occurs in the rural areas, mainly due to the relatively large use of biomass, while the lowest level of emissions is recorded in a typical suburban household. Also, the analysis shows that fuel switching in domestic cooking activities from biomass to LPG and kerosene can be used as a measure to reduce emissions due to higher stove efficiencies and lower emission factors associated with these fuels. Substitution of 50% of biomass usage by kerosene in the rural households will result in 39-50% reduction in emissions within the rural sector. Further, substitution of 50% of biomass usage in urban and suburban sectors by LPG results in 4-49% reduction in emissions within these sectors.