The dielectric constants and losses have been determined for solutions of o-hydroxyacetophenone, 1-chloro-and 1-bromonaphthalene and 2-chloro- and 2-bromonaphthalene in dilute solutions of 15 °C involving a nonpolar solvent. Either seven or eight microwave frequencies were employed over a wide range from about 1 to 145 GHz, and the relaxation times of the molecules were such that the high frequency side of the Cole–Cole plot near the dielectric constant at high frequencies (ε∞) was well defined. For these polar solutes in nonpolar solvents no high frequency deviations from the Cole–Cole plot are apparent in the plot itself based solely on microwave data. In a few cases the distribution parameter was negligible (less than 0.03) and in one case it was zero. In all cases a Cole linear plot and also a Brot plot revealed the existence of additional absorption to that contributed by molecular relaxation. Such additional absorption would have been difficult to be certain of from the Cole–Cole plot alone when the distribution parameter was either negligible or very small. The frequency points at about 70 and 145 GHz are invaluable in detecting such additional high frequency absorption contributions.