A YAG: Nd laser system is described which supplies giant pulses which are within 3% constant in shape and size and do not depend on the pump energy and the shape of the pumping pulses. A LiNbO3crystal cut at the Brewster angle is used as aQswitch. Since the oscillation of the laser in the off state is used to open theQswitch, a definite inversion always occurs within the laser rod at the instant the switch opens that is due to the threshold of the off state and depends solely on the cavity characteristics. The height of the giant pulses is moreover easily controlled by varying the voltage applied to the LiNbO3crystal.