Three different zeolitic catalytic systems (13X, 5A and Ammonium Y) were tested for their dielectric properties, surface area and pore-size distribution. The 13X catalyst conductance is higher than other catalysts. The activation energies for 13X, 5A and Ammonium Y are 100, 80, and 50 kJ/mole respectively. The capacitances of 13X catalyst increase with increasing temperature causing a complex behaviour at higher temperatures and frequencies while the capacitances of 5A catalyst are usually less than 10 pF and those of Ammonium Y catalyst are erratic at low temperature. The 13X catalyst is the most suitable catalyst for its dielectric properties and proves to have a good potential to be heated by a RF dielectric reactor. The BET surface area in m(2)/g are 524 +/-2, 353 +/- 1 and 684 +/- 3 while the average pore diameters (in Angstrom) by the BET technique are 33, 22, 26 and the micropore volumes in cm(3)/g are 0.187, 0.125 and 0.220 for 13X, 5A and Ammonium Y respectively.