A non-contact, optical methodology suitable for high temperatures based on laser-Doppler vibrometry is presented to directly determine piezoelectric constants. LiTaO₃ is chosen as a model material as it is a representative piezoelectric material with applications in sensors and surface acoustic wave devices. The values determined range from 12 pm V^-1 at 21 °C to about 15 pm V^-1 at 400 °C, being in good agreement with the literature. Thus, the proof of concept for this approach has been obtained.