The dipole moments of the ethylene derivatives acrylonitrile, chloroacrylonitrile, methyl vinyl ketone, vinyl bromide, 1,1-dichloroethylene, and tribromoethylene were determined in benzene solution at 20 °C. The measured dipole moments were corrected for the solvent effect by the method of Looyenga. In addition the applicability of the Looyenga equation for the solvent effect was tested on earlier reported data for 20 different molecules, whose dipole moments were derived from dilute benzene and carbon tetrachloride solutions, respectively. The corrected dipole moment values were compared with earlier corrected values calculated according to the method of Le Fevre and Le Fevre and with reported gas values. It was found that for most compounds both methods of correction yielded dipole moment values which differed by 0–10% from the gas values.