A bone anchoring assembly for dynamic stabilization is provided, comprising a bone anchoring element (2) having a head (4) and a shank (3) to be anchored in a bone or a vertebra, and a receiving part (5) for receiving a rod (8), the rod (8) having a flexible section which is made at least partly of a polymer material. The receiving part (5) comprises a first channel (58) with an approximately U-shaped cross-section with two free legs (52, 53). Furthermore, a locking element (7) is provided directly cooperating with the legs (52, 53) to secure the rod (8) in the first channel (58), wherein a first pin-shaped projection (73) is provided at the locking element (7) which comes into contact with the flexible section of the rod (8) when tightening the locking element (7) in such a way that in the tightened state the integral structure of the rod (8) is not violated.
