A dynamic stabilizing device (1) for bones (3), in particular for vertebrae, includes two bone anchoring elements (2) spaced from one another, which are connectable via fastening elements (4) with at least one rod (5) that is at least partly elastic. The rod (5) has an adjustable device (7) for affecting its elasticity, which is adjustable before and/or after the implantation of the stabilizing device (1). The adjustable device (7) is formed, such that it changes the free length of an elastic section (11) of the rod (5). The adjustable device (7) includes a carriage that is displaceable over the rod (5), and the carriage (20) engages the rod (5) on a peripheral side at least partially.