The ink jet print heads produced by Spectra utilize piezoelectric material's shear mode movement to deflect one pressure chamber wall, generating a pressure differential for the ejection of a drop of ink from the orifice connected with the pressure chamber. The responses of a piezoelectric transducer to the applied voltages determine the characteristics of pressure pulses that drive the jets. Direct measurement of the dynamic responses of piezoelectric transducer can provide valuable information not only for a better understanding of the shear mode movement, but also for the optimization of a print head design. It also provides reliable information to verify numerical models that can be applied quickly to various aspects of future printhead development work. However, owing to high operating frequency and tiny shear mode movement of the piezoelectric transducer the measurement is often challenging.This paper investigates the capability of laser Doppler vibrometer in measuring the displacement of Spectra's shear mode piezoelectric transducer. Measurements have been conducted on a fully functional 128 jets, 600 dpi commercial compact print head (CCP128/600). Displacements smaller than 0.02 μm at high jetting frequency have been successfully measured. It has been demonstrated that laser Doppler vibrometer can be effectively used to evaluate printhead dynamics, identify potential problems, verify numerical models and optimize the printhead designs.