The crystal structures of isomertieite, Pd₁₁Sb₂As₂, (I) from the Monche-Tundra intrusion, Monchegorsk Igneous Complex (MIC), Kola Peninsula, Russia, and törnroosite, Pd11As2(Te1.7Bi0.3)R2 (IIa) and Pd₁₁As₂ (Te_1.3Bi_0.7)R2 (IIb) from the South Sopcha intrusion, MIC, Kola Peninsula, Russia, were refined on the basis of X-ray diffraction data collected from single crystals. The two minerals were found to exhibit the same structure, cubic, space group Fd3m, Z=8, with unit-cell parameters for (I): a 12.297(5) Å, V 1859.3(2) ų; for (IIa): a 12.350(2) Å, V 1883.6(4) ų; and for (IIb): a 12.370(1) Å, V 1892.9(3) ų. The structures were refined to R1=0.056 (I), 0.014 (IIa), 0.018 (IIb). The isomertieite crystal-chemical formula was confirmed. The Bi-for-Te substitution in törnroosite was found to not affect the main structural topology. In the structure of the two minerals there are three symmetrically independent Pd positions: M1, M2, and M3. M1 forms M1As₄ tetrahedra, M2 forms M2As₂Sb₂ (I) or M2As₂Te₂ (II) tetrahedra, and M3 forms M3Sb₃ (I) or M3Te₃ (II) triangles connected together via common edges and forming a framework in the structure.