Centrifugation method and chamber for washing and continuous separation of blood constituents. This chamber comprises at least one first intake channel for the blood, at least one second intake channel for a sterile washing solution, at least one first outlet channel for at least one constituent of this blood, and at least one second outlet channel for a fluid composed of said washing solution and of the other blood constituents. The second intake channel has its downstream end continued on its periphery by a circular deflector. The latter extends into the bottom of the chamber and is terminated along its inner cylindrical side wall by a ridge, which defines a passage of annular cross section for the flow of said sterile washing solution.