Abstract: The present invention relates to a process for the continuous preparation of a polyolefin in a reactor from one or more ?-olefin monomers of which at least one is ethylene or propylene, wherein the reactor comprises a fluidized bed, an expanded section located at or near the top of the reactor, a distribution plate located at the lower part of the reactor and an inlet for a recycle stream located under the distribution plate wherein the process comprises—feeding a polymerization catalyst to the fluidized bed in the area above the distribution plate—feeding the one or more ?-olefin monomers to the reactor—withdrawing the polyolefin from the reactor—circulating fluids from the top of the reactor to the bottom of the reactor, wherein the circulating fluids are compressed using a compressor and subsequently cooled using a heat exchanger to form a cooled recycle stream comprising liquid, and wherein the cooled recycle stream is introduced into the reactor using the inlet for the recycle stream wherein a part of th