The title compound, [Cu(ClO(4))(2)(C(3)H(4)N(2))(4)], was obtained unexpectedly by the reaction of copper(II) perchlorate hexa-hydrate with equimolar amounts of 1-chloro-1-nitro-2,2,2-tripyrazolylethane in methanol solution. The crystal structure comprises octa-hedrally coordinated Cu(2+) ions, located on an inversion centre, with four pyrazole ligands in the equatorial plane. The average Cu-N distance is 2.000 (1) Å. Two perchlorate ions are coordinated to copper in trans positions [Cu-O = 2.4163 (11) Å].