A bone anchoring device includes a bone anchoring element having a shaft and a head; and a receiving part for coupling a rod to the bone anchoring element. The receiving part includes a first portion with a U-shaped recess for receiving the rod, and a second portion for accommodating the head, the second portion having a free end and being flexible so as to allow introduction and clamping of the head. The bone anchoring device also includes a locking ring embracing the second portion. The head is locked by means of exerting pressure with the rod onto the locking ring resulting in compression of the second portion of the receiving part and wherein the locking ring is mounted to the receiving part from the free end of the second portion.