We report on a technique of passivelyQswitching an Er:YAG laser operating at 2.94 &mgr;m. TheQswitch consists of a high refractive index prism having one total internal reflection surface in contact with an absorbing liquid. The initial losses were achieved via attenuated total reflection. Using the aboveQswitch, pulses with up to 85 mJ having 130–140 ns pulse width were generated. The output was linearly polarized and the spacial beam profile was nearTEM00.The laser was operated at 2 Hz repetition rate. ©1998 American Institute of Physics.