Plutonium selenide forms black crystals of a cubic system, space group Fmm, cell parameters a = 0.57934 nm, Z = 4, structure of the NaCl type.
With increasing pressure, two phase transitions occur: at 20 GPa into the trigonal system and at 35 GPa into the cubic system, a structure of the CsCl type.
Its magnetic susceptibility follows the Curie-Weiss law.