The crystal structure of the title compound, [[Cu(en)(2)][KCo(CN)(6)]](n) (en is ethylenediamine, C(2)H(8)N(2)), reveals a novel three-dimensional porous framework in which [Cu(en)(2)](2+) acts as a template and K(+) as a connecting unit. The Cu atom lies on an inversion centre and the Co and K atoms are on twofold axes.