The invention relates to a waste treatment method in which waste is subjected to a first screening process (4). The fraction of waste passing through the screening is subjected to a pre-fermentation treatment in a rotating tube (1) and the material leaving the pre-fermentation treatment tube is subjected to mixing in a mixing hopper, and, subsequently, to a methanization treatment in a digester (2). The organic materials are separated from the undesirable products in the material leaving the pre-fermentation treatment tube before it enters the digester. The digester (2) is horizontal and mechanically stirred, and a fraction of the digestate leaving the digester is recirculated at least in the mixing hopper, the recirculation rate being sufficiently high to ensure complete mixing.