The crystal structure of jaguéite, ideally Cu₂Pd₃Se₄, monoclinic, a 5.672(5), b 9.909(9), c 6.264(6) Å, ß 115.40(2)º, space group P2₁/c, has been solved by direct methods and refi ned to an R1 index of 5.52% for 956 unique refl ections measured with MoK X-radiation on a P-4 Bruker diffractometer equipped with a CCD area-detector. The crystal structure of chrisstanleyite, ideally Ag₂Pd₃Se₄, monoclinic a 5.676(2), b 10.342(4), c 6.341(2) Å, ß 114.996(4)º, space group P21/c, has been solved by direct methods and refi ned to an R₁ index of 8.3% for 1203 unique refl ections measured with MoK X-radiation. There are two unique Pd sites, one Cu (or Ag) and two Se sites in the unit cell. Atom Pd1 forms isolated square arrangements PdSe4, whereas the adjacent arrangements involving Pd2 are paired via a common edge. The (Cu,Ag) coordination tetrahedra form (100) layers which, together with the Pd2-Cu(Ag)-Pd1-Cu(Ag)-Pd2 system of metal-metal bonds, help to stabilize the open-work structure composed of PdSe₄ squares.