Polyaxial bone anchoring device that includes a bone anchoring element (1) with a rod (2) to anchor it in a bone or vertebra and a head (3)； a housing part (4, 4 ') to accommodate a rod (5) to be connected to the bone anchoring element (1), the housing part including a first end (4a) and a second opposite end (4b), a central axis (C) that passes through the two ends, a channel for housing the rod (5), a first coaxial bore (9) at the first end (4a) and a second coaxial bore (12) at the second end which is in communication with the first drill (9)； an insert (6, 6 ', 6' ') that can be assembled and mounted on the housing (4, 4'), including the insert (6, 6 ', 6' ') a seat ( 18) for the head of the bone anchoring element (1) in order to allow the head to rotate with respect to the seat, the insert (6, 6 ', 6' ') of the second bore (12) protruding and this having a bounding edge at one end (6b) opposite the first bore (9) with an opening (17) that is smaller than the head, to prevent the head from passing therethrough； and the bounding edge being configured to allow the bone anchoring element (1) to rotate a greater angle in a first place of the bounding edge than in another place of the bounding edge with respect to the central axis (C)； and the insertion piece (6, 6 ', 6' ') being able to rotate with respect to the housing part, characterized in that the housing part (4, 4') has a first flat surface part (13) essentially perpendicular to the central axis (C) to support the insert (6, 6 ', 6' ') and the insert (6, 6', 6 '') having a second corresponding flat surface part (15a) located opposite the first part of flat surface (13), and because the bone anchoring device further comprises a pressure element (7, 7 ') configured to move in the housing in the direction of the axis of the first bore and which only enters head contact (3) to exert pressure on it.Dispositivo de anclaje óseo poliaxial que incluye un elemento de anclaje óseo (1) con un vástago (2) para anclarlo en
