The crystal structure of dehydrated fully $Cd^{2+}$-exchanged zeolite A evacuated at $2{ imes}10^{-6}$ Torr and $450^{circ}C (a = 12.225(2){AA})$ and of its ethylene sorption complex (a = 12.219(2) ${AA}$) have been determined by single crystal X-ray diffraction techniques in the cubic space group Pm3m at $21(1)^{circ}$. The structures were refined to final error indices, $R_1$ = 0.063 and $R_2$ = 0.065 with 266 reflections and $R_1$ = 0.055 and $R_2$ = 0.062 with 260 reflections, respectively, for which $I{gg}3{sigma}(I)$. In both structures, six $Cd^{2+}$ ions lie at two distinguished three-fold axes of unit cell. Dehydrated $Cd_6$-A sorbs 4 ethylene molecules per unit cell at $25^{circ}C$ (vapor pressure of ethylene is ca. 100 Torr). Each $Cd^{2+}$ ion forms a lateral ${pi}$ complex with an ethylene molecule. Four $Cd^{2+}$ ions exist in a nearly tetrahedral environment, 2.210(7)${AA}$ apart from three framework oxygen ions (considering ethylene molecule as a monodentate ligand) and $2.67(6){AA}$ from each carbon atom of ethylene molecule.