Polysiloxanes with mesogenic side chains are suitable model compounds for the study of molecular dynamics. The first dielectric relaxation data are presented here for a cyclic oligosiloxane having a degree of oligomerization of 5, a cyanophenylbenzoate group as the terminal dipole, and a spacer lengths of 3. The phase sequence was determined by means of X-ray diffraction, differential scanning calorimetry, and polarizing microscopy. Reasons for the strong dependence of physical properties on the degree of oligomerization are discussed.