In the present work, different scenarios for the treatment of the organic fraction of municipal waste at regional scale are proposed and assessed by means of LCA. The geographical area under study is Catalonia (Spain). The current Catalan waste management scenario treating 1218 Gg of organic waste is analyzed and compared to a new scenario treating the same amount of waste but fulfilling the European Landfill Directive and the new recently approved Catalan waste management plan. As final disposal (incineration and sanitary landfill) of untreated municipal solid waste is not permitted, the new scenario includes increasing anaerobic digestion treatment of source selected organic fraction of municipal solid waste while maintaining the existing composting plants for this type of waste. Gaseous emissions treatment equipment will be provided when not installed in composting plants. Home composting is also included. Non-source selected organic fraction of municipal solid waste will be treated by composting. Different scenarios for sensitivity analysis have also been proposed dealing with the influence of transport, fugitive methane emissions from anaerobic digestion plants and the use of compost among other issues. The new scenario proposed decreases the impact in five out of the six impact categories studied (from a 49% in eutrophication potential to a 9% in ozone depletion potential). The inclusion of methane fugitive emissions in anaerobic digestion installations in impacts calculation impairs the environmental benefits of this type of treatment facilities (increasing global warming potential value up to a 31%). Improvement of landfill gas collection is of utmost importance in decreasing global warming potential. ©