A bone anchoring device is provided comprising:a receiving part (5) for coupling a rod (6) to a bone anchoring element (1), the receiving part (5) comprising a first end (5a), a second end (5b), a central axis (C) extending between the first end (5a) and the second end (5b), a recess (53) for receiving a rod (6), wherein by the recess (53) two open legs (53a, 53b) are formed and wherein the legs are configured to cooperate with a fixation element (9), and a head receiving portion (54) at the second end (5b) for pivotably holding a head (3) of a bone anchoring element (1), the head receiving portion (54) being at least partially flexible and having an opening at the second end (5b) for inserting the head； anda locking ring (8) mounted at least partially around the head receiving portion (54), wherein a rotational movement of the locking ring around the central axis (C) provides a force which causes the head receiving portion (54) to be compressed.
