In the present case study, the causes of the high vibrations on a double-drive cement mill is investigated by performing a series of vibration measurements on the cement mill pinion and the main bearings, and on the concrete foundation with a multichannel vibration analyzer. FFT (Fast Fourier Transform) and ODS (Operational Deflection Shapes) measurements were made to find out the dominant frequencies of vibration energy and the behaviour of the concrete structure at this particular frequency. Through the use of the “Operational Deflection Shapes” technique together with FFT analysis the main source of the vibration generation mechanism was identified. In the ODS method, the vibrations of the selected points on the structure in the measured direction are recorded with recpect to a reference signal. This information is then processed to simulate the vibration of the structure in the measured direction. In the present case 10 points on the foundation were selected and the vertical vibrations of the foundation were measured. As a consequence, the source of the vibrations on the mill was identified as the asymmetry and the weakness of the foundation structure.