Construction, laboratory tests as well as the first field application of a new fibre-optic rotational seismograph is presented. The system based on fibre-optic gyroscope (FOG) with measured Angle Random Walk on range 10−8 rad/Sqrt(s) and a few rad/s maximum detectable amplitude of rotation in frequency range from DC to 328.12 Hz designed it for rotational seismology area of interest. This work presents also exemplary relevant measurements which were conducted using two seismographs in the geophysical observatory in Książ region, Poland.