Abstract: A method of cooling the primary circuit of a pressurized water nuclear reactor in which, after a first stage, during which water is injected into the steam generators and the steam produced is discharged, cooling is continued during a second stage by water-water heat exchange. In this second stage, the water is made to circulate at the secondary side of at least one steam generator (2) in countercurrent to the primary water, over at least part of its path. The secondary water heated by the primary water is cooled outside the containment enclosure (1) of the nuclear reactor in at least one heat exchanger (31) using raw cooling water. The secondary water is recycled in the steam generator (2). The invention is applicable to the effecting an maintaining of cold shutdown of pressurized water nuclear reactors.