Toughened thermoplastics are prepared by mechanically dewatering a water-moist elastomer component A containing up to 50% by weight of residual water and mixing the resulting dewatered elastomer component A' with a thermoplastic polymer B in a mixing unit, by a process in which the elastomer component A is fed to a twin-screw extruder which has corotating, in each case triple-flight, screws and essentially includes, in the transport direction, one unheated metering section in which the elastomer component A is fed to the extruder by a metering means, at least one squeeze section which serves for dewatering and contains at least one retarding element and in each case at least one associated dewatering orifice, at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder, at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements, at least one devolatilization section which is provided with at least one devolatilization orifice and in which the residual water is removed as steam, and unheated discharge zone, and in which the water emerging from the dewatering orifices is present partially or completely in the liquid phase.