A polyaxial bone anchoring device includes a bone anchoring element having a head, a receiving part having a channel for receiving a rod and an accommodation space for pivotably holding the head, and a pressure member having a pressure exerting surface and a deformable portion with a free end. The deformable portion is adjustable from a first configuration where a first part of the deformable portion is supported at a first axial position relative to the receiving part while a second part of the deformable portion protrudes further radially into the channel than parts of the deformable portion positioned axially above the second part, to a second configuration where the second part of the deformable portion is deformed radially outwardly and the pressure exerting surface is shifted lower axially to exert pressure on the head while the first part of the deformable portion remains supported at the first axial position.
