Dielectric properties of concentrated w/o emulsions in the frequency range 40 MHz to 4 GHz were investigated by means of the time domain spectroscopy (TDS) method in the presence of an external high voltage field. All investigated samples show a dielectric dispersion due to the interfacial polarization inside the aqueous droplets. All the dielectric parameters (εs, εs−εinfinand τ) are dependent on the magnitude of the external field. At higher electric fields, the coalescence is promoted. The dependence of the droplet size distribution, the strength of the applied field, the orientation of the droplets relative the electrical field on the dielectric parameters is discussed for these concentrated emulsions.