Ln6(mu 6-O)(mu 3-OH)(8)(H2O)(24)]I-8(H2O)(8) (Ln = Nd, Eu, Tb, Dy) compounds are obtained as the final hydrolysis products of lanthanide triiodides in an aqueous solution. Their X-ray crystal structure features a body-centered arrangement of oxygen-centered {Ln(6)X(8)}(8 +) cluster cores: [Nd-6(mu(6)-O)(mu(3)-OH)(8)(H2O)(24)]I-8(H2O)(8) [Pearson code oP156, orthorhombic, Pnnm(No. 58), Z = 2, a = 1310.4(3) pm, b = 1502.1(3) pm, c = 1514.9(3) pm, 3384 reflections with I-0 > 2 sigma(I-0), R1 = 0.0340, wR2 = 0.0764, GOF = 1.022, T = 298(2) K], [Eu-6(mu(6)-O)(mu(3)-OH)(8)(H2O)(24)]I-8(H2O)(8) [Pearson code oP156, orthorhombic, Pnnm(No. 58), Z = 2, a = 1306.6(2) pm, b = 1498.15(19) pm, c = 1499.41(18) pm, 4262 reflections with I-0 > 2 sigma(I-0), R1 = 0.0540, wR2 = 0.0860, GOF = 0.910, T = 298(2) K], [Tb-6(mu(6)-O)(mu(3)-OH)8( H2O)(24)]I-8(H2O)(8) [Pearson code oP156, orthorhombic, Pnnm(No. 58), Z = 2, a = 1296.34(5) pm, b = 1486.13(7) pm, c = 1491.88(6) pm, 4182 reflections with I-0 > 2 sigma(I-0), R1 = 0.0395, wR2 = 0.0924, GOF = 1.000, T = 298(2) K], and [Dy-6(mu(6)-O)(mu(3)-OH)(8)(H2O)(24)]I-8(H2O)(8) [Pearson code oP156, orthorhombic, Pnnm (No. 58), Z = 2, a = 1296.34(5) pm, b = 1486.13(7) pm, c = 1491.88(6) pm, 3329 reflections with I-0 > 2 sigma(I-0), R1 = 0.0389, wR2 = 0.0801, GOF = 0.992, T = 298(2) K.