Supplementary to a preceding investigation on primary amines, the dielectric loss increments of three aromatic dimethylamino compounds, diphenylamine, N-methyldiphenylamine and triphenylamine, and of dicyclohexylamine have been measured in very diluted solutions at 20 °C. The loss data resulting from 0.1 up to 250 cm -1 are now covering the complete absorption region due to reorientation of the permanent molecular dipole, especially that part based on inversion. To resolve this part, the absorption curves are analysed in terms of three areas using the same method as done for primary amines. By this the dipole components assigned to the special reorientation processes may be discerned and discussed. So the dipole component of the dimethylamino group which reorientates by intramolecular motion is smaller than that of the amino group. The occurrence of an inversion process is demonstrated, but the molecular dipole component governing it also may reorient more slowly as the result of a hindered inversion. The additional reorientation of a mesomeric moment by twisting of the phenyl groups is suggested in triphenylamine and in the diphenyl compounds. The aliphatic dicyclohexylamine only shows a Poley absorption area, increased perhaps by intramolecular libration.