The invention relates to a process for pelletizing polymer melts, at above ambient pressure, in a pelletizing chamber into which a cutting apparatus has been inserted. In a first step, the pelletizing chamber is flooded with a gas which is inert toward the polymer melt and whose pressure is that at which the pelletizing process is carried out. The polymer melt is then injected into the pelletizing chamber. Finally, the gas is displaced from the pelletizing chamber via a liquid as soon as the polymer melt begins to flow through the cutting apparatus, this melt being cut into pellets.