The European energy policy promotes the production of biomethane from biogas, and so many plants are reconverting from electricity to biomethane. This study has estimated the potential production of biomethane in Southern Italy, which typically has a Mediterranean climate. The aim of the research was developed according to the current standards for energy production without impacts on food and feed. For this purpose, using the Land Use Efficiency (LUE) Index, the environmental sustainability of the biomethane potential of the study area was calculated. The first step was to quantify the amount of ‘integrated biomass' obtained by agro-industrial processes, the crop areas dedicated to energy production, and the extent of the animal herds involved in producing biomethane by anaerobic digestion process. Subsequently, the most efficient biomass production mix for anaerobic plants was determined and the rate of producible biomethane was estimated. The results estimate that about 200 biomethane plants could be built to produce 250 Nm3 of CH4 hourly, without determine deep changes in the traditional agricultural systems. This highlights the strategic role of biomethane in Southern Italian agriculture and, more generally, in an area often characterised as economically and socially marginalised.