Abstract: Adjustment system for the pitch angle of a wind turbine, which wind turbine includes an axis of rotation that is horizontal or at a small angle with respect to the horizontal plane, and a rotating hub to which the blades are connected in a manner allowing their slewing, in which system an adjustment arrangement is arranged inside the hub and/or shaft. The arrangement includes a drive device moving in the direction of the axis of rotation as well as an adjustment cylinder apparatus or corresponding for moving it. Rod-shaped control parts for each blade are connected in a hinged manner to the drive device. The control parts are connected to the butt part of each blade such that the pitch angle can be adjusted by shifting the drive device.