A method for stabilizing at least one frame part of a forest work unit involves determining a moment applied by a payload of the forest work unit to a frame part to be supported and determining a magnitude and direction of at least one support moment needed at least for stabilizing the frame part on the basis of the moment applied by the payload to the frame part to be supported. An arrangement for stabilizing at least one frame part of a forest work unit comprises means for carrying out said determinations.
