An ultrasonic diagnostic imaging system for shear wave measurement transmits push pulses into tissue for the generation of shear waves. Characteristics of the shear waves such as their velocity of passage through the tissue are measured to assess properties such as tissue stiffness. The measurements are compensated for effects of background motion by sampling echo signals from the tissue at different times and comparing the samples to detect the presence of relative motion between the ultrasound probe and the region of interest where shear waves are detected. Sensed background motion is used to adjust measured shear wave characteristics.