In this investigation we used ultrasonic energy to decalcify 10 mitral and six aortic valves after they had been surgically removed. The calcium was disintegrated in all cases and normal valvular tissue was preserved. The fragments of disintegrated calcium were collected in a suction bottle, which prevented peripheral embolism. The ultrasonic urologic probe is an unwieldy instrument for cardiac surgery, and we suggest the manufacture of a new probe for clinical use in our specialty.