Abstract: In the case of a method for balancing rotors, more particularly tool holders of machine tools, the imbalance of the rotor is ascertained in a computer, in terms of size and direction, of a balancing machine and is compensated by spreading at least two balancing elements with a predetermined imbalance into suitable positions of adjustment. Firstly from the measured imbalance of the rotor and the size of the imbalance of the balancing elements the position of adjustment of the balancing elements is determined and then the rotor of the balancing machine is turned until a balanced position is reached, at which the position of adjustment of the one balancing element is at a predetermined position in relation to the balancing machine. When the rotor is located in the balanced position, a visible marking is projected onto the balancing element. The balancing element is then set in its position of adjustment by bringing a mark provided on the balancing element into alignment with the visible marking.