In the title complex, [Cu(C13H11N3O2)2(C12H8N2)](NO3)2, the CuII atom (site symmetry 2) is coordinated by four N atoms from one 1,10-phenanthroline and two hydrazine ligands, respectively. The hydrazine ligands coordinate to the CuIIatom by a pyridine N atom. These four atoms form a slightly distorted square-planar N4 donor set. In the packing, two additional Cu⋯O interactions occur [Cu⋯O = 2.462 (2) Å], resulting in a typical Jahn–Teller-distorted octahedral environment around the Cu atom. N—H⋯O hydrogen bonds result in a three-dimensional network. The O atoms of the anion are disordered over two positions in a 0.68 (2):0.32 (2) ratio.