In the title complex, [Cu(4)Cl(4)(C(58)H(52)N(2)P(4))](n), four Cu(II) atoms are held together via two doubly bridging and two triply bridging chlorides, forming a stair-like Cu(4)Cl(4) core having crystallographically imposed inversion symmetry, while the benzene-1,4-diamine ligand (with a crystallographic inversion center at the centroid) acts in a tetra-dentate coordination mode, bridging two adjacent Cu(4)Cl(4) cores, resulting in a chain along the a-axis direction. One Cu atom has a distorted tetra-hedral geometry, coordinated by one P atom, one μ(2)-Cl and two μ(3)-Cl atoms, while the second Cu atom adopts a trigonal geometry, coordinated by one P atom, one μ(2)-Cl and one μ(3)-Cl atoms.