The invention relates to a device for granulating thermoplastics that are extruded from nozzles, the latter being provided in a nozzle disc in a substantially circular arrangement. Blades, which rotate about a blade carrier shaft and are held by a blade carrier in an oblique position in relation to the radial direction, sweep over said nozzles. The blade carrier shaft runs through the centre of the circular assembly and a cooling medium is fed to the nozzle disc and the blades to cool the granulated plastics. The blade carrier, together with the blade carrier shaft, is located in an essentially circular housing, which extends as far as the nozzle disc and into which a supply of cooling medium flows in a tangential direction, in order to create a circulatory stream in said housing containing the rotating blade carrier. The cooling medium rotates in the housing at a speed and in a rotational direction that essentially correspond to the rotational speed and rotational direction of flow passages in the blade carrier, by means of which the cooling medium is fed to the blades.