This paper deals with the topic of calibration of piezoelectric displacement generator. The precise length measurements laboratory at the Faculty of Mechanical Engineering and Naval Architecture does not have a system of measurement and procedures to calibrate such instruments. The aim of this paper is to develop a system of measurements that will be used to calibrate piezoelectric displacement generators. The system of measurements that was developed can be divided into two subsystems: the subsystem with the piezoelectric displacement generator and the subsystem with the laser interferometer that ensures the connection with the definition of metre. The basic elements of the system of measurements are described in the first part of the paper and they are: interferential laser system, piezoelectric displacement generator and retroreflector with all the technical data later used to assess measurement uncertainty. The second part of the paper presents the devised system of measurements, describes the procedure of its adjustment, the measuring procedure and the results with the assessed measurement uncertainty. An analysis of the data that was measured was done in the end and it presents the application of the system of measurement for the calibration of piezoelectric displacement generator that was developed.