Hydrothermal (deuteratothermal) reaction of L-ethyl lactate (Lig-Et) with Eu(ClO(4))(3)6 H(2)O gives colorless block crystals of [Eu(Lig)(2)(X(2)O)(2)][ClO(4)] (1, X=H; 2, X=D) both of which possess a two-dimensional laminar homochiral framework. Single-crystal dielectric measurements reveal that 1 and 2 display a giant dielectric anisotropy approximately exceeding 100 and large isotopic effect with about 54 % enhancement along the a axis. Their ferroelectric features further confirm this respect. Crystal parameters: 1, C(6)H(14)ClO(12)Eu, M(r)=465.58, monoclinic, C(2), a=8.6786(6), b=8.3965(6), c=10.2153(7) A, beta=92.040(1) degrees , V=743.92(9) A(3), Z=2, rho(calcd)=2.079 Mg m(-3), R(1)=0.0508, wR(2)=0.1239, mu=4.448 mm(-1), S=1.043; Flack=0.04(5). 2: C(6)H(10)D(4)ClO(12)Eu, M(r)=469.61, monoclinic, C(2), a=8.689(2), b=8.410(2), c=10.224(3) A, beta=92.057(4) degrees , V=746.7(3) A(3), Z=2, rho(calcd)=2.089 Mg m(-3), R(1)=0.0465, wR(2)=0.1150, mu=4.432 mm(-1), S=1.058; Flack=0.02(5).