A coordination polymer, [Cu5(piv)5]n (piv = pivalate), was prepared by a thermal decomposition method. The unit cell of the crystal structure consisted of one right-handed helical chain and one left-handed helical chain, which were formed by an alternation of Cu(I) ions and carboxylate (O-C-O) groups. This chain possessed a pseudo-5(3) screw axis; the second-order structure was suggested to be realized by a balance between the cuprophilicity and a steric effect of the tert-butyl groups.