Laser ultrasonic technique has been successfully applied to a sample embedded in a transparent pressure transmitting medium to measure sound velocity at high pressures in a diamond anvil cell. Shear and longitudinal acoustic wave velocities are measured both for an opaque sample, Fe, and a transparent pressure transmitting medium, KBr, at pressures ranging from 0.3–24.8 GPa. The small sample size used in this experiment for sound velocity measurements suggests great potential for using this technique to evaluate the elastic properties of solids at pressures approaching 100 GPa and for other samples embedded in soft, transparent pressure transmitting media such as KBr or argon.