A process for producing bio-oil from municipal solid waste, the process including: a) liquifying municipal solid waste, to obtain a mixture containing an oily phase containing bio-oil, a solid phase, and a first aqueous phase; b) treating the first aqueous phase from a) with an adsorbing material, to obtain a second aqueous phase; c) fermenting the second aqueous phase from b), to obtain a biomass; d) subjecting the biomass obtained in c) to the liquification a). The bio-oil obtained is advantageously used in the production of biofuels for motor vehicles or for the generation of electric energy or heat.