Abstract: An adjustable damping force vibration damper for vehicles and the like is provided which includes a cylinder filled with damping fluid and a working piston axially moveable within the cylinder and dividing the cylinder into first and second spaces. Damping valves are disposed in surrounding relationship to the piston and serve to communicate damping fluid between the first and second cylinder spaces during relative movement of the working piston and cylinder during use. A damping level adjusting mechanism is provided for adjusting the flow of damping fluid between the first and second cylinder spaces, including a connecting duct disposed in bypassing relationship to the damping valves. An external actuated slideable control piston is disposed for controlling the opening of the connecting duct between the two cylinder spaces.